Firestop Accessories are used in conjunction with our other Firestop Sealants and Foams etc. During a fire, electrical boxes become easy passages for smoke and flames to bypass fire-rated walls. Metacaulk has developed Electrical Outlet Cover Guards which can easily be added underneath an outlet or switch coverplate. The Cover Guards are "intumescent" which means the material will expand when exposed to elevated temperatures caused by a fire and block the opening in the wall. Another electrical box firestop accessory is the Metacaulk Box Guards which are intumescent and installed in the back of the switch or outlet box. Other fireproofing equipment includes masonry trowels for spreading firestop sealants and caulk guns for dispensing firestop caulk from their cartridges. Mineral Wool Safe/Safing insulation is used as a void filler prior to applying firestop sealants and caulks. Mineralwool Safing is a high temperature non-combustible rock based fiber insulation that is the preferred filler for firestop applications.