40mm Carbo Air Fiddle Block with Swivel & BecketLow-friction Carbo Air blocks are lightweight, strong, reliable-and affordable. Companions to the popular HarkenA(R) Black MagicA(R) line, these small, compact blocks have very high working loads for safe, easy trimming. The 40 mm fiddle is an excellent choice for 3:1 and 4:1 tackles on dinghy vangs and mainsheets, as well as for controls such as cunninghams and internal boom outhauls on larger boats.Specifications: Sheave: 40mm / 1-9/16in Length: 131mm / 5-1/8in Weight: 54g / 1.9oz Shackle pin: 4mm / 5/32in Maximum line: 10mm / 3/8in Maximum working load: 220kg / 485lb Breaking load: 735kg / 1620lb