Series 40 AP Block Double Becket Swivel HeadRonstan blocks Ball Bearing Series 40.Features:Exceptionally high working loadsLow maintenance, long service lifeSelf-lubricating sheaveCaptive Lock™ universal headSlotted pin shackle eliminates fouled linesAll 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.Applications:MainsheetHalyardVangSpinnaker control lines on off-the-bench catamarans, one design classes and sportsboats up to 8m (26ft)Materials:UV Stabalized Acetal sheavesImpact and UV resistant, fiber reinforced Nylon cleatsGrade 316 stainless steel bearing race