Hubbell-Raco 1218-5 Bushing, Insulated, 2-Inch Trade Size, Grounding, Lay-In Lug, Mall, Threaded, Rigid/IMC Conduit Malleable iron construction insures mechanical protection for the raceway Zinc electro plated for corrosion protection Dual rated aluminum grounding lugs may be used with copper or aluminum grounding conductors 2 in. Trade size: ground wire #14 solid - #4 stranded