3M™ Fire Barrier Cast-In Device Height Adaptors are one-piece extensions that provide up to four inches (10.2 cm) of additional height to 3M™ Fire Barrier Cast-In Devices. No fasteners are required and installers simply snap the adaptor onto a metallic or non-metallic cast-In device. Adaptors adjust to accommodate concrete slab pour depths up to 12 inches (30.5 cm) thick. Adaptor/device assemblies are firestop tested up to three hours.