Barrel Unions to suit pump barrel unions. These are a very common circ pump used in spas. 40mm Connection suits 1.5" BSP tails.. Tail is approx 55.5mm diameter. Nut is ~73mm including ridges. Picture shows a pair, but comes as one set. Nut, Tail, O-ring.

Fits Aquaflo - FMCP, FMHP, Circ-Master, and EHT Therma-flo bath pumps, and others.

Aqua-flo Pump FTG 1015-A ABS 1 1/2 Compression