Rectorseal 66703 Metacaulk Firestop Joint Strip 3" x 82 'Rectorseal 66703 A flexible firestop material used in concrete masonry control floor wall joints up to 2" (51 mm) wide. Forms a strong char preventing passage of flame, smoke, hot gases between control joints. Can use with plastic pipe penetrations. Features Easy to install and Cost effective Versatile, Flexible Highly intumescent (multiple staged) Forms a strong char to prevent passage of flame, smoke and hot gases May be covered with any color