NSi FireStop™ Pillows are a single step firestop system component. They are intended for wall and/or floor openings through fire separations where temporary or permanent firestops are required. They are ideal where cable retrofitting is frequent and anticipated. These pillows allow for quick and clean single product installation. Pillows are self-supporting – no wire lath or mesh is required. They are to be packed tightly into the voids between penetrating items and the perimeter of the opening. During a fire, the intumescent component within each pillow dramatically expands to seal the opening from fire, thereby maintaining the integrity of the fire separation. FireStop™ Pillows consist of an intumescent layer sandwiched between non-combustible insulation, all enclosed in a hermetically sealed polyethylene shell. No sealant or putty is required. Easy to install, easy to remove – a quick and clean single product installation. ASTM E 814 and UL 1479.