Self centering bunk glide on's made with Tie Down's enhanced PVC. Launch and load made easy. Ideal for painted, fiberglass, or aluminum boats. Slide on or off with less effort. Easy to install. Includes 2 left and 2 right self centering glide-ons with rounded end caps to fit two 2" x 4" x 8' bunk boards. Includes stainless screws.