The Fire & Acoustic Door Drop Seals are designed for the gap between the door bottom and floor,it provides an excellent barrier to airborne sound and helping to ensure that the acoustic attenuation provided by a door set. 

The Fire & Acoustic Door Drop Seals control the movement of the inner sealing strip through mechanical movement . When the door is closed , internal sealing strip will be down automatically to performance the tight sealing effects. When the door is opened, the inner seals will be automatically rise from the floor. Some of this serious seal can be fully hidden in the door bottom groove, the door beautiful surface will not be affected by installation of the seal.