Shipshape Roller Bunks quickly, easily and economically transform bunk style trailers into roller style trailers. Made of heavy gauge galvanized steel for long-lasting rust protection; Non-marking rollers with end caps glide smoothly to support boat; Pre-assembled and pre-drilled for easy installation; Sold in pairs. When mounted with brackets (sold separately), roller bunk adjusts vertically and angled to hug boat hull; Also may attach directly on top of flat bunk board. AVAILABLE SEPARATELY: 4' Pair Shipshape Roller Bunks - word search in our Store for 'Shipshape Roller Bunks'. 5' Pair Shipshape Roller Bunks