Series 50 All Purpose Block - TripleFeatures: Exceptionally high working loads; Low maintenance, long service life; Self-lubricating Acetal polymer sheave ensures low friction and extreme durability; Slotted pin shackle eliminates fouled lines; Lockable swiveling head post; Snap fit removable becket pin; 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.Head can be locked at 0 or 90 by engaging the grub screw in either the 0 or 90 degree position.Applications: Mainsheet and halyard applications, vang and spinnaker control lines on boats to 10m (33ft); S60 - on boats up to 12m (40ft); Materials: Grade 316 stainless steel load strap; Impact and UV resistant, fiber reinforced Nylon cheeks; - cis2:mm5mnJlm -