FL8017 -- 3/4" & 1" Tap Adaptor Suits 3/4"(19mm) or 1"(25mm) threaded tap FL8018 -- 1/2" & 3/4"Tap Adaptor Suits 1/2"(13mm) or 3/4"(19mm) threaded tap FL8018-A--1/2" & 3/4"Tap Adaptor ? Material:brass ? Durable nickel plating on a solid metal body