SpecSeal® FP intumescent Firestop Plugs are soft and supple, foam plugs molded from polyurethane. Plugs are conveniently sized to fit 2 in (51 mm) or 4 in (102 mm) diameter openings or sleeves fabricated from electrical metallic tubing (EMT). The intumescent plugs expand when exposed to heat to quickly close off around combustible jacketed cables. The SpecSeal® FP500D Firestop Plugs are conveniently sized to fit 5 in (127 mm) diameter openings or steel sleeves. When exposed to heat they quickly close off 1-1/2 in or 2 in trade size ABS, PVC steel or iron drain pipes.