Trailer Bunk Glides (Kit of 4 Glides under 60 inches; kit of 2 60 inches or more) Fiberglass and aluminum boats, PWC and pontoons easily glide on and off Surfix Trailer Glides. Kit of 4 ( less than 60" ) kit of 2 ( 60 " or longer ) Solid High Density Polyethene .45 thick glides provide full bunk support; no more uneven spaced pads to leave marks on the hull. No thin skin to break down and expose a cost saving Injection molded honey comb or understructure to grind against the hull. Low profile stainless steel wide pan head screws embrace the flat deep mounting pockets. No counter sunk screws to spread the plastic and work them loose or through the material. Quarter-rounded top perimeter and square base provides snug butting and a no-snag transition between glides. Start the glides at the rear most edge of the bunk the quarter-rounded top will be the first contact to slide on the hull; no need for a different ending cap. The bright white color allows you to easily see and wash off any sand or road dirt that can scratch your hull. Sold as a kit of 4 glides ( less than 60 Inches ) or a kit of 2 ( 60 inches or longer )