These Jabsco port kits allow Jabsco Par-Max 2.9, Par-Max 3, Par-Max 4, Par-Max 5, old model Par-Mate pumps and Jabsco accumulator tanks to adapt to different sizes of hose and plumbing. The plug-in port part measures 19mm (3/4″) diameter and simply snaps-in for easy change or replacement. Supplied in pairs. J25-143 – 12mm (1/2”) I.D