MPT-Deck Plug is made of inorganic fibers derived from basalt, a volcanic rock, with thermosetting resin binder. Advanced manufacturing technology ensures consistent product quality, with high fiber density and low shot content, for excellent performance in firestopping assemblies. MPT-DP is a high density mineral wool manufactured in a trapezoidal shape to fill voids in metal decks in Head-of-Wall (HWD) where deck flutes are perpendicular to adjoining fire rated walls.