Hook to eye turnbuckle 12mm made of heavy duty galvanised steel. The hook-to-eye adjuster will adjust from 254mm to 342mm. Turnbuckles or straining/rigging screws are commonly used to properly tension cables, ropes and rigging systems on boats, such as mast and sail rigging, safety lines, as well as various other deck hardware. Eye diameter: 18mm, inside hook: 13mm, body length: 140mm.