The Balboa Water Group O-Ring 2" gasket 21619 is the perfect choice for creating water tight seals on Balboa heaters with 2" unions. It's designed to provide an optimal fit and superior performance that only Balboa heaters can offer.

The inside diameter of this gasket measures 2-1/8", while its outside diameter is 2-5/16". This gasket will fit almost all spa heaters made by Balboa, including models from the Lite Leader, GS, VS and M7 series. It also fits perfectly with Balboa's 2" split nut.