Ronstan Series 40 Single Block with universal head. All purpose (AP) blocks are a great all around solution. Self-lubricating Acetal polymer sheaves running on polished stainless steel races perform equally well with dynamic loads and high static loads. For durability and a long service life, these blocks are the right choice for sheets, halyards and control line applications for cruising and racing. Captive Lock? universal head can be fixed in either of two planes, or free to swivel as required. Exceptionally high working loads. Low maintenance, long service life. Self-lubricating sheave. Captive Lock? universal head. Slotted pin shackle eliminates fouled lines. Used for mainsheet, halyard, vang lines. Also for spinnaker control lines on off the beach catamarans, one design classes and sports boats up to 8m. Made from U.V. stabilised Acetal sheaves. Impact and U.V. resistant, fibre reinforced Nylon cheeks. Grade 316 stainless steel bearing race. Grade 316 stainless steel load strap and head fitting. Impact and UV resistant, fibre reinforced Nylon cheeks. Dimensions: Sheave?? ?40 mm Max. Rope ? 10 mm Pin ? 5.0 mm