For additional functionality the head design Features a swivel head which incorporates a locking grub screw mechanism to allow the block to be set in correct alignment

All Optiparts boom end fittings are made of high quality glass fibre filled nylon and have a firm grip around the mast to ensure the mast and boom always turn together

the head may be left to freely rotate when in the unlocked position

stretch cuffs and neck seals with hook-and-loop adjustments

brilliant step in achieving a truly professional marine finish

Ronstan Series 40 Upright Lead Block, All Purpose RF41171 coastal For additional functionality the headRonstan SERIES 40 AP Upright Lead RF41171 Sheave 40 mm Max. Rope 10 mm Max. Cable 4 mm Fastener 5. 0 mm M. W. L. 400 kg B. L. 1000 kg Weight 59 g