QM99EO Panic Rim Exit Device with Quiet Mechanical Option Length:3'0" (2'4" to 3'0" Doors) it also keeps your door

it also keeps your door in constant alignment

ThermoSeal insert helps with acoustic performance

310-2-3/4OB-F-24D-630

Mechanical backcheck

QM99EO Panic Rim Exit Device with Quiet Mechanical Option Length:3'0" (2'4" to 3'0" Doors) it also keeps your doorVon Duprin QM99EO Grade 1 Quiet Mechanical Rim Exit Device, Wide Stile Pushpad, Panic Rated, Exit Only, Hex Dogging High performance, wide stile heavy duty rim exit device for high use and abuse applications The Von Duprin QM option controls motion to reduce operational noise. The QM rim device option provides damper controlled re latching. For optimal quiet performance of your total opening, use the Von Duprin QM option along with a properly adjusted