Metacaulk wrap strip is a flexible strip of highly intumescent firestop material used primarily for plastic and insulated pipe applications. When exposed to heat, it expands and forms a strong char to seal off the penetration and prevent the passage of flames and hot gases. Easy-to apply - simply wrap the required number of strips around penetrating item and push into annular space. May also be used with a universal collar. US patent no. 6,207,085 FBC system compatible indicates that this product has been tested, and is monitored on an ongoing basis, to assure its chemical compatibility with FlowGuard Gold, BlazeMaster and Corzan pipe and fittings. FBC, FlowGuard Gold, BlazeMaster and Corzan are licensed trademarks of the Lubrizol Corporation.