CE Smith Heavy Duty Swivel Flush Mount Rod Holder-Replacement Parts and Accessories for Tournament Fishing,  Rod Fishing, Deep Sea Fishing and Trolling 1-3/4" inner diameter; 2-1/4" outer diameter 10-1/2" tube + adjustment nut is 12" in total length Adjustable resistance swivel gimbal; unbreakable cast gimbal cup Smooth Acting Clutch Cap 5-1/8" long x 4-1/4" wide