Extension rings provide a means for adding additional cubic capacity or as an outlet box for surface conduitCombination screw heads provide for faster installationFire resistance acceptable for use in 2 hr rated wallsConduit wiring system50 lb static fixtureDrawn construction(4) 1/2 inside knockouts
RACO® 128 Extension Ring, 2 Gangs, 4 in L x 4 in W x 1-1/2 in D, Steel