This thing allows mounting of an Istep above ground pool entry ladder to a Bestway or Intex steel frame above ground pool. The top rail of these pools are oval. Use an 8mm x 50mm bolt or a 5/16" x 2" bolt and a matching nut. Drill the istep mounting strap holes out to 8mm or 5/16". Press bolt through rail mount. Press nut into printed wing nut. Press mount on to rail of pool. Slide mounting straps from ladders over bolts through corresponding holes in straps. Spin wing nut onto bolt. Now includes a mount for XTR frame pools too!