3M™ fire barrier cast-in device metal deck adaptors are one piece plastic body adaptors for one step fire stopping on fluted metal decks. Installers simply snap a metallic or non-metallic 3M™ fire barrier cast-in device into the adaptor - no fasteners are required - and attach it to the metal decking before concrete slabs are poured. Adaptor/device assemblies are firestop tested up to 3 hours.