Our Patented Angel Ventlock® are the most effective Child Fall Prevention devices you can buy. We designed them to help keep your children safe.

Often known as window restrictors or window opening control devices (WOCDs), Angel Ventlocks® are the choice of many window manufacturers all over the world and we have solutions for sliding and gliding, single and double hung sash windows. In addition, we have versions for OEM factory-fitting and retrofittable devices for installers or the homeowner.

This specification establishes the installation, safety, performance, and labelling requirements for devices intended to address the risk of injury and death associated with accidental falls from windows by children five years old and younger. All Angel Ventlock® have passed ASTM rigorous testing standards. Most restrictors haven’t.

For further information about ASTM F2090 standards, visit the site here

Secured by Design (SBD) is the official police security initiative that works to improve the security of buildings and their immediate surroundings to provide safe places to live, work, shop and visit.

SBD’s product based accreditation scheme – the Police Preferred Specification – provides a recognised standard for all security products that can deter and reduce crime. Visit the site here

All Angel Ventlocks® have been recognised by the SBD scheme. Most restrictors haven’t.

Always ask our advice before purchasing an Angel Ventlock. It is vital you purchase the right product for your window. Our devices only work with windows where the sash to Frame gap is fixed and cannot vary. Call us on 01223 497097 to make sure our devices are suitable for your window.

If you fit our device to a window that it was not designed to fit, you can endanger the lives of those you are trying to protect. Call us before buying or fitting an Angel Ventlock.

To comply with AASTM F2090-21 regulations, you have to fit two Single-action devices OR one Dual-action device to your window. This is because focus group testing has shown a child can overcome one Single-action device if fitted on its own, but not two when fitted together. Similarly, a child cannot  overcome one Dual-action device.

So, if you are fitting Angel Ventlock® to a vertically sliding sash window (Single or Double-Hung) you will require a pair of single-action devices from our range. Single-action devices require only one operation to operate the device.

If you are fitting an Angel Ventlock® to a horizontal sliding sash window, you will require a Dual-action device. Dual-action devices require two simultaneous operations to operate the device.

Always ask our advice before purchasing an Angel Ventlock. It is vital you purchase the right product for your window. Our devices only work with windows where the sash to Frame gap is fixed and cannot vary. Call us on 01223 497097 to make sure our devices are suitable for your window.

Yes, we designed the three versions of  Angel Ventlock®, Retrofit (Standard, Shallow and Flat Bend) Single action devices for exactly that purpose. Sold as a pair, you  fit one either side of the window to comply with ASTM F2090-21

For use primarily on Timber and Aluminium windows (but can also be fitted to Vinyl and Fibreglass units where suitable fixing is available), the devices are fixed to the vertical stiles of the top sash.  Device selection is dependent on your sash to frame clearance.

Please go here to view the options. 


Always follow the fitting instructions provided with your product. You can find them here. One thing that is consistent is that the device(s) should be fitted so that they limit the sash opening to 4″ (100mm) or less. For more information, please go here.

We have both keyed and keyless options in our range. Never fit the keyed version to an egress window (one you may need to escape through). For Egress windows, use our non-lockable versions as these are keyless and therefore cannot be locked. They are easily operated by an adult and automatically reset once the window has been shut providing a level of security and of course, reducing the risk of window falls.

We deliver to the UK (excluding the Republic of Ireland), EU and internationally. Mila Hardware who are based in Dublin can provide our Angel Ventlock® products. You can contact them here

You can find more information on our delivery policy and charges here and our terms & conditions here.

If you would like to make a bulk order, please get in touch with our team so that we can understand your requirements and help you further. You’ll find more useful information on our Commercial page.

Window restrictors can be purchased from most DIY, joinery or hardware companies. There are many different types on the market, depending on your requirements. The important thing to note is that not all window restrictors conform to US/UK or European standards.

It’s easy enough to childproof a window yourself, whatever type of windows you have in your home. Do some research into the best restrictors for your window and ensure you’re checking reviews and reputation. Most restrictors can be fitted relatively quickly, and they come with step-by-step instructions on how to do it.

The Angel Ventlock® conforms to US/UK and European safety standards. Ask your tradesman for Angel Ventlock®.

In order to safely fit the Angel Ventlock®, we provide in depth instructions, so it’s possible for you to easily do this yourself. If you’d like more information, take a look at our Resources page.

Fitting a window restrictor is not as difficult as you might think and many companies will give detailed instructions on how to do it yourself. If you are considering fitting a window restrictor to either childproof your window or for added security, in most cases they are easily installed by homeowners!

Take a look at fitting videos, as this can often make it simpler. If in doubt, always contact a specialist. It’s very straight forward to fit the Angel Ventlock® and you can find full instructions and video on our website by clicking here.

Ultimately, it is the responsibility of the window manufacturer or end customer to ensure the product works on their windows, that they are tested after installation and the end user is provided with details on how and when to test and maintain their WOCDs.

There aren’t many window restrictors that reach the US, British and European Standards, which is what allows them to be referred to as ‘Window Opening Control Devices’ (WOCDs), so doing your research on the best restrictor for your window is imperative.

Aesthetics also play a part in the kind of restrictor you should purchase, as some are more discreet than others. This can be particularly useful if you are installing in a child’s bedroom and want to make them as hidden from view as possible. If your main aim is for child security, the window shouldn’t be able to open anymore than 100mm. The Angel Ventlock® is designed to be opened by an adult or a child over 6 years of age for emergency egress. Angel Ventlock® will automatically reset when the window is closed.

Many restrictors can be retrofitted to a window, but others will need to be fitted at the time of window manufacture/installation, so this is another point to consider when selecting the right window restrictor for your needs.

A Window Opening Control Device (WOCD) is designed to prevent a sash window from being open any more than 100mm/4inches. The device should also allow the sash to open properly when needed for emergency egress.

Restricting a window to this limit also ensures window safety for children, as a bigger gap can not safely keep children inside. Using products such as window screens is not enough to keep children safe in the home, so window restrictors for sash (hung) windows is the ideal solution to prevent accidents.

Keyless window restrictors are fitted to windows to help prevent children from opening a window to a point where they would be able to fall out of it. There are a variety of window restrictors on the market, suitable for all types of windows including casement and sash.

By purchasing a keyless window restrictor, it is still easily accessible should you need to exit in case of a fire or other emergencies.

The kind of lock you’ll need for your window, depends on the type of the windows you have in your home. There are already many hazards around the window area, such as; window screens which can be easily popped out; blind cords can be wrapped around the neck; and open windows that are not secured sufficiently. Products such as the following can help with childproofing windows in your home;

Window Stoppers: These prevent a window from being opened too wide, allowing only a narrow gap. When childproofing a window, it should open no further than 100mm wide.

Angel Ventlock®: Created for sash windows, the locks prevent the sash from being pushed up too far. The window can still be opened for ventilation, but not too far that a child could get through the gap.

It’s natural curiosity that causes children to play and investigate everything – which is why window safety is paramount and it’s necessary to lock your windows. Adding locks to your window is quicker and easier than you might think. It’s possible to have the Angel Ventlock® added by a sash professional during window fitting, but equally the Angel Ventlock® can be added retrospectively by you. You’ll find more information on how to fit the Angel Ventlock® window restrictor by visiting our Resources page.

Ultimately, it is the responsibility of the window manufacturer to ensure the product works on their windows, that they are tested after installation and the end user is provided with details on how and when to test and maintain their WOCDs.


Windows are a weak spot in any home and should be secured correctly to ensure there is adequate protection. It’s not just about keeping intruders out either – it’s about keeping little ones safely inside and window locks are vital in doing this.

Some window locks are unfortunately not safe, which is why researching window locks is so important – don’t always go for the cheapest option! You should always ensure you’re choosing the best lock for the type of windows in your home. Research the company, read reviews and be sure that the lock you’re choosing is compatible with your window. Avoid products which are poor quality and won’t withstand vigorous force. 

If you have an older home, it may have traditional sash windows and in these cases you will need to look for a lock that allows you to keep the window secure, but also accessible for egress, ventilation and ease of cleaning. If you don’t feel confident installing your own locks, contact a specialist who will be able to ensure they’re fitted correctly. Many locks can be fitted retrospectively, although some have to be fitted at the time of window installation – always check the lock you’ve purchased is suitable.

Locking windows is not a fire hazard – as long as easy egress in an emergency is possible. Some window locks on the market are difficult to open, and this can create obstacles in exiting during a fire.

The main focus of a window lock is to prevent someone entering your home and preventing children from falling out. However, there are many window locks that enable you to achieve these things, whilst still allowing you to exit through the window during an emergency.

Window restrictors and sash locks can often be purchased without needing keys to open them, which makes egress far quicker and more effective. Something like a ventlock allows effortless access in case of a fire, whilst children of a certain age are unable to open the window, keeping them safe day-to-day.

Open windows are an obvious risk to children, but during the summer months it is important to ventilate a house adequately. This creates problems for parents as there are very few options that ensure your child is completely safe. 

If you have an awning window, consider installing a restrictor so that the gap in which it can be opened is limited and a child can’t get through. These are also ideal for casement windows.

If you have a sash (hung) window instead, something like a ventlock can be purchased, which restricts you from fully opening the window up. A small gap allows ventilation, whilst being too narrow for children to get through. Even though they are keyless, children are unable to operate the locks themselves. With any lock you plan on purchasing, always ensure they are checked to US, British and European Safety Standards.