Wide Application: These trailer boat guides are suitable for ski boats, fishing boats, or sailboat trailers, and they make loading the boat so much easier. With Carpet Boards: The two 24" carpet-padded boards can be fixed firmly onto the tubes, and they will prevent the boat from being scratched. Add the frames effortlessly and keep your boat protected. Solid Construction: These square brackets are made of 0.12" thick steel and are powder-coated, so they work great against saltwater and do not easily bend or rust. Flexible Installation: Our trailer guide-ons can be mounted on top of the frame or below it, and the U-bolts fit both large frames and smaller frames. Adjustable Width: The width of these boat guide-ons can be easily adjusted, extending to 8 inches at most. They are compatible with trailer frames less than 3" wide and 4-1/4" tall.