Frequently Asked Questions

Often known as window restrictors or window opening control devices (WOCDs), Angel Ventlock® are the choice of many window manufacturers all over the world and we have solutions for horizontal sliding and hung 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. The earliest version of the standard is ASTM F2090-08 (2008) other issues have been 2010,2013,2017 and the latest current issue is ASTM F2090-21 (2021). Angel ventlocks comply with all of the issues.

For further information about ASTM F2090 standards, please contact ASTM International.

Secured by Design (SBD) is the official UK 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

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. You can find contact details on our Contact Us page.

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 ASTM F2090-21 regulations, if you have hung windows, you are need to fit a pair of our Single-action devices. If you have a horizontal sliding window you need to fit one of our Dual-action devices 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, the testing concluded a child cannot  overcome one Dual-action device.

So, if you are fitting Angel Ventlock® to a vertically sliding hung 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 each device.

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

Yes, we designed the three versions of  Angel Ventlock™ Retrofit (Standard, Shallow and Flat Bend) Single action device 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 dependant 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 advise you never fit a keyed restrictor to an egress window (one you may need to escape through). Our devices are non-lockable and suitable for ease of egress. 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.

The correct choice of Angel Ventlock® is dependant on the type, style and construction of your window.

If you are in doubt as to which to choose, please call your local representative details on our Contact page.

Ultimately, if you are manufacturing windows, it is your responsibility to ensure the product works on your windows, is tested after installation and the end user is provided with details on how and when to test and maintain their Angel Ventlock®. Details of testing and maintenance routines are available on our resources page.

If you are installing windows for someone else’s use, it is your responsibility to ensure the product works on the window, is tested after installation and the end user is provided with details on how and when to test and maintain their Angel Ventlock®. Details of testing and maintenance routines are available on our resources page.

If you are have purchased an Angel Ventlock® device to fit in your home, it is your responsibility to ensure the product works on the window, is tested after installation and the product is regularly tested and maintained. Details of testing and maintenance routines are available on our resources page.

We are happy to work with you to develop a size that works for you. MOQs or Minimum order values may apply.

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. ASTM F 2090 21 states “Window manufacturers who rely on a test report from the supplier of the window fall prevention device shall verify that the installation of the window fall prevention device (either installed by the window manufacturer prior to shipping of the window or provided by the window manufacturer as a field installed kit) on their specific window product operator type complies with this standard.” This means the manufacturer shares responsibility for making sure the device meets the standard after installation. 

Contact the Sales Representative for your state here for more information.