CE Smith, adjustable keel roller bracket, pair, wired, galvanized. Mounts on any trailer tongue to hold a roller for keel support. Length determined by your roller and trailer tongue. Mounting: add 1" to tongue width to determine length of the two 3/8" mounting bolts. Roller: add 2" to tongue width to determine correct roller width. shaft: add 3" to tongue width to determine 5/8" shaft length. Fasteners and roller, not included.