METACAULK FIRESTOP PILLOWS is fire stop cushion , non asbestos used to prevent distribution fire and hot gas. when happen contact with fire form charcoal hard. METACAULK FIRESTOP PILLOWS usually applied in cable installation stripe or horizontal pipe that has big aperture. very easy installed and can moved as according to need. for use more economical this product can at combine with METACAULK FIRE RATED MORTAR.