This%20kit%20includes%20everything%20you%20need%20to%20mount%20a%20RAM%20Ball%20on%20a%20kayak%20or%20boat%20rail%2C%20like%20the%20ones%20on%20the%20Hobie%20Pro%20Angler.%20The%20base%20has%20an%20upper%20and%20lower%20that%20sandwich%20tightly%2C%20using%20the%20provided%20U-bolts%2C%20onto%20a%20square%20or%20round%20rail.%20This%20kit%20includes%20a%201.5%20inch%20ball%2C%20base%2C%202%20U-bolts%20and%20hardware.Accommodate%20rails%201%2F2%20to%201-1%2F4%20inches%20in%20diameter.