Aluminum Cam & Groove Adapter, Male Half, 2-1/2 Inch Male NPT

Youre looking at a male cam and groove adapter with 2-1/2 inch male NPT pipe threads. It mates by sliding into a compatible cam and groove coupler and locking down the cam levers by hand.

Cam and groove fittings made to standard A-A-59326 or DIN 2828 are interchangeable across manufacturers, so this adapter should mate up with any coupler built to those same standards. The one exception worth knowing is the half-inch and eight-inch sizes, which have no formal standard and often don't play nice between brands. At two-and-a-half inch, you're in the range where interchangeability holds.