One-piece plastic body assemblies used to create a void around aerators. For use with 4 in. (101.6 mm) metallic or non-metallic 3M™ Fire Barrier Cast-In Devices
Primarily used in new installations when firestopping 4 in. (101.6 mm) pipes that pass through flat concrete decks with a 6-1/2" (165.1 mm) minimum concrete topping. Device with adaptor are installed on forms prior to the concrete pour to create a void at the bottom of the concrete slab surface.