AA Size per the ASSE 1010 standard;Products indicated as "No Lead" comply with national no lead product material requirements and comply with NSF 61, which allows the product to contain no more than 0.25% lead;Straight sweat models are compatible with press-fitting systems, and all push-fitting systems;Straight compression models install on any 1/2" nom. copper leg or riser – perfect for replacing air chambers;MIP thread models install on any new rough-in or retrofit installation with 1/2" FIP fittings;CPVC solvent weld models install on 1/2" CPVC tube or fittings in rough-in or retrofit applications;PEX models are available with F1807, F1960 and F3347 connections;Hose tee model installs on washing machine supply valves or directly to washing machine