3M FIRE BARRIER PASS-THROUGH DEVICE 

Fire barrier devices offer an effective one-piece solution for the fire stopping of penetrating items through rated walls and floors. During a fire, these devices in tumesce to form a seal, which helps protect against the spread of fire, smoke and toxic gases.
> Available in 51 mm round, 64 mm square, 102 mm round and 102 mm square sizes
> Hot and cold smoke seal
> Stack-able for penetrate versatility
> Hinged for easy retrofit installation around cables
> Provides up to a 4-hour fire rating