1-1/2", Zinc, Water Tight Conduit Hub, Indoors Or Outdoors, Water Tight, Insulated Throat, Use To Connect Rigid Or IMC Conduit To A Load Center Or Other Metal Enclosure Where A Water Tight Joint Is Required At Knock Outs Or Slip Fit Holes, Flame Retardant Lexan Insulated Throat, Rain, Oil, & Dust Tight, Oversize Locknut Assures Vibration Proof Installation & Positive Grounding.