Designed for the 230mm Diamond Dome Sunpipe, the Diamond Dome Sunpipe Intumescent Fire Collar is designed to delay fire spreading into the loft space of any house. Fitted above the ceiling plasterboard and separate from Diamond Dome Ceiling Diffuser. The intumescent fire choke collar consists of two 0.9mm steel parts which clamp around the aluminium sunpipe tube designed to crush the tube creating a solid barrier when exposed to fire. This blockage is rated to prevent the spread of fire into the roof space by up to 2 hours.