Ronstan Series 20 Ball Bearing Orbit Block - Single - Dyneema Lashing - Becket Option. It's so light that it needs to be lashed down Specifications for Ronstan Series 20 Ball Bearing Orbit Block: Manufacturer: Ronstan Color: Black Features of Ronstan Series 20 Ball Bearing Orbit Block Integrated stainless steel hub to accept lashing attachment and through-sheave becket Suits up to 4mm(5/32") lashing Includes 750mm (30") x 1.7mm(1/16") diam lashing Applications: Control lines on dinghies and catamarans to 5M(16') Materials: Sheave: High compression strength carbon acetal Ball bearings: stainless steel Frame/Cheeks: Nylon Package Contents: Ronstan Series 20 Ball Bearing Orbit Block Ronstan RF25109: Series 20 Ball Bearing Orbit Block - Single - Dyneema Lashing - Becket Option