Overall Height: 205 mm Width: 195 mm features: Dorgard is a device designed to safely hold open a fire door and automatically release the fire doors upon the sound of a fire alarm. It can be used to hold the fire door open in any position. Unlike electro-magnetic retainers (EMR), Dorgard requires no wiring as it is battery operated and self-contained. Installation is easy, quick and non-disruptive. It is affixed to your fire door with four screws and takes approximately 5 minutes to install. Once you have inserted two C-size batteries (supplied), Dorgard is ready for duty. When Dorgard is holding open a fire door it listens for a continuous fire alarm sound level of over 65 decibels. After approximately 14 seconds it will release, allowing the fire door to close under the pressure of the overhead door closure. Fire doors weighing more than 120kg, which have a closing force in excess of 120 Newton metres (that\'s a closing force of about 15kg, 800 mm from the hinge) must have the Floorplate installed in combination with the Dorgard unit. Please call our sales team for more information or a product leaflet.