aka Window Opening

Control Devices


For a Window Opening Control Device to meet the ASTM F2090 standard, it must be applied in a way that limits the window opening to less than 4 inches, needs two motions to open it (such as holding it open against a spring while simultaneously moving the window past it), and it must automatically reset when the window is closed.  Window Opening Control Devices should not be confused with window opening limiters (devices such as those that clamp onto the track, wedge the window, or block the track like window sticks) that do not carry the "two motion" characteristic necessary to make it a Window Opening Control Device.  These might be sold as "window security" devices, but they may not qualify as a Window Opening Control Device.

Window Guards classified as fall prevention devices are found inside the window.  They consist of horizontal or vertical bars (sometimes netting in place of bars) which are inserted into holding bars that are screwed into the inside window frame.  The guards are released by depressing two separate, spring-loaded pins and collapsing the telescoping tubes into themselves, thus reducing the size of the guard so it can be removed from the holding bars. 

Safety Screens are a specialized screen device that can retrofit to an existing window.  "Normal" window screens have a basic function of keeping insects out when the window is open.  A normal screen has a nylon or light metal mesh held into an aluminum frame by wedging the screen fabric into a groove so that it is held in place with a rubber cord inserted into the same groove.  Safety Screens are of a more robust design and intended to provide a level of strength that can meet child safety standards while serving as an aesthetically appropriate screen that also keeps out insects.   It uses a steel mesh clamped into a steel frame to create a much more rigid assembly. 


Product Availability

​KidCo, maker of Window Stops, has offered StopAt4" visitors a special deal.  Use this link KIDCO to access their web site.  Use the promo code "windowsafe10" between now and the end of 2020 to receive 10% off your order.

Some products may be available at area stores.  If you have difficulty finding product, please use the "Contact" page of this web site with questions.

Alternative Products

Not every window situation has conventional solutions.  For example, older children, or young adults, can have conditions that make window safety a priority.  These individuals can overcome traditional window opening control devices designed to safeguard young children.


A Canadian company called Jax Mobility carries several devices that may provide solutions.  While these devices do not meet the ASTM F2090 standard that the devices above meet, it does not mean they are not a reasonable solution in certain cases. 


REMEMBER:  Windows must provide safe escape in an emergency and the ability for firefighters to enter in an emergency.  Non-ASTM F2090 devices must consider this.  Part of the solution is to ALWAYS have and maintain your working smoke alarms in the home.  In the event of a fire, they will provide early warning for escape through normal doors.  Have smoke alarms on each living level of the home (within 15 feet of each sleeping room) and inside each sleeping room.  Test them regularly to ensure they are continuing to protect your family.