CE Smith Pontoon Square Rail Adjustable Clamp-On Rod Holder, 55108A. Comes with 2 protective liners, one to fit 1" and one to fit 1-1/4" square rail. The liners are round on the outside allowing the rod holder to be adjusted to any angle above the water, and the hidden left or right adjustment allows even more adjustment choices ((in 15 degree increments). Plastic insulator sleeves are included to help provide snug fit on the rail. Gimbal pin keeps your rod from spinning. Solid bottom with drain holes prevents water from pooling.