This kit includes everything you need to mount a RAM Ball on a kayak or boat rail, like the ones on the Hobie Pro Angler. The base has an upper and lower that sandwich tightly, using the provided U-bolts, onto a square or round rail. This kit includes a 1 1/2 inch ball, base, 2 U-bolts and hardware.
Fits 1” to 1.25” rail.