Self centering bunk glide on's. Makes launching and loading easy! Fits 2x4 standard bunk board. Slide on and off with less effort. Easy to install. Sold in pairs of 4' sections (1 left & 1 right). Kit includes 1-4' left piece and 1-4' right piece. Example: if you have a set of 8' bunks you would need to order two kits.