The Driftmaster Li'l Pro Series 3/8" Thread Round Clamp Base for 7/8" rails can be used with any Li'l Pro Series rod holder. The base can be easily adjusted by loosening 1 nut and turning the base on the rail, allowing you to control the angle of your rod. Features a 3/8" diameter threaded center hole. Driftmaster Li'l Pro Series 3/8" Thread Round Clamp Base - Marine Accessories at Academy Sports