Ronstan ball bearing Orbit Blocks™ boast the highest strength-to-weight ratio available, achieved through all-composite reinforced polymer materials and multiple attachment options. Ultra low profile through-sheave becket. Uses: mainsheet systems and spinnaker sheets on dinghies to 5m (16ft); halyard, vang and backstay applications on boats to 5m (16ft); and control line applications on larger yachts.
Specifications: 1-3/16" (30mm) sheave diameter; 5/16" (8mm) maximum rope size; 661 lb. maximum working load; 1323 lb. breaking load; weighs 1.1 oz.