3M PT4TMB ~ Fire Barrier Pass Through Triple Mounting Brackets Pair 4 in Square 7000059408 Width_36 Inch This boom helps prevent leaks Size_42 Inch This boom helps prevent leaks and spills from spreading to adjacent surfaces 3M Virtua Reader Protective Eyewear 11513 00000 20 is designed for workers who have difficulty reading small print or are engaged in detail work the 4 inch x 12 inch 3M Fire Barrier Pass Through Triple Mounting Brackets PT4TMB provide additional support to the device when installing three devices stacked (vertically or horizontally) together in a 1 x 3 array Used in conjunction with three 4 inch square 3M Fire Barrier Pass Through Devices