Barton Stainless Ball Bearing Block Double Swivel/Bkt 30mm A robust stainless steel block with a multitude of uses on all types of sailing boats. Highly polished side plates with flared cheeks prevent the possibility of chafing the line whilst giving added strength. These are ideal for use on dinghies and dayboats for kicking straps or wherever a compact or powerful rope tackle is required. Sheave dia: 30mm Sheave width: 11mm Max rope diameter: 8mm SWL: 280kg Break load: 560Kg Length: 100mm Weight: 82g