3M™ fire barrier moldable putty pads mpp+ are a one-part, ready-to-use, in tumescent wall opening protective. When properly applied to the back of electrical outlet boxes, 3M™ fire barrier moldable putty pads mpp+ help control the spread of fire, smoke and noxious gases through fire restive walls and partitions. Installed in accordance with the ul wall opening protective listing (UL category CLIV), the product helps achieve up to 2-hour ratings in a variety of wall constructions. 3M™ fire barrier moldable putty pads mpp+ can effectively provide protection for back to back electrical boxes. 3M™ fire barrier moldable putty pads mpp+ are also used as a firestop material in through-penetration firestop systems 3M™ fire barrier moldable putty pads mpp+ help to maintain a firestop penetration seal for up to 4 hours. 3M™ fire barrier moldable putty pads mpp+ exhibit excellent adhesion to a full range of construction substrates and penetrants. The pads are easily molded by hand (no mixing required). In addition to its fire-resistant properties, the 1/10th in (2.54 mm) thick pads have airborne sound reduction characteristics which helps minimize sound transmission through assemblies requiring an STC-Rating.