Waterway 1 1/2 Bt x 1 1/2 Spig Heater Tailpiece 417-4050 for Split Nut

 2 left , then discontinued - includes flat gasket with integrated o-ring . Part 717-4050 with 711.4050 gasket included for 1 1/2 inch plumbing.

Waterway 1-1/2" buttress thread x 1/1/2"spigot heater tailpiece. This tailpiece has a spigot connection on back that fits inside another 1 1/2 inch PVC slip connection.

Waterway  1 1/2 Bt x 1 1/2 Spig Heater Tailpiece 417-4050 for Split Nut. 

Does not include o-ring - need an o-ring?  See O-125

Or a flat 1 1/2 inch heater gasket 711-4000

Or a flat gasket with integrated o-ring 711-4050

Originally a union nut such as 415-5000 may be present on a pump such as Vico Ultra pumps, but a split nut may be needed.

This union is usually used with RS101 Dreammaker Spa heaters.