size: 1/2", 3/4", 1", 1-1/4", 1-1/2", 2", 2-1/2", 3", 3-1/2", 4" ITEM NO. 540~549 540S~549S 540A~549A material: Zinc Die Casting, Steel, Aluminum Die Casting EMT setscrew coupling for corresponding EMT conduit. Coupling (steel) is constructed out of steel and has a zinc electro-plate covering. This coupling is concrete tight when taped. Setscrew type couplings used to connect two lengths of electrical metallic tubing. Assembled with die cast locknut and tri-combo screws. American Standard Die cast from high strenth zinc alloy. Listed for use with steel and aluminum EMT, IMC, and rigid conduit. For more products catalog please contact our company.