Very common Water-line light fitting / housing found in many Signature, Designer, Leisurite, Lanark, Heritage, Four Winds Spas, Bullfrog Spas, Morgan Spas, Sunbelt Spas and other Spa Industries Spas. Also found in many Chinese imported spas.
These often break due to over-tightening, and with age. Some manufacturers used the o-ring, and some did not.
Uses 12mm Hole. 17mm Face.
Light Wall Fitting, RD, MINI POL, 1/2"HS, 11/16"FD, CLEAR
Rising Dragon Pinnacle Light System