3/4" I.D. Copper Adapter Kit Comes with 2 copper tubes, 2 large plastic nuts and 2 gaskets ( # 54F ) Used to connect to Autotrol Valves ( like 163, 168, 263, 268 )directly or to any Autotrol By Pass. Commonly used with Autotrol 155 and 255 By Pass valves. Alternate part # 1001606