Quite simply, Ronstan Ratchet Orbit blocks™ have the highest holding power available. The sophisticated NC-machined sheave features Generation 2 of our patented sheave cross-hole geometry. The Series 40 delivers up to 14:1 holding power, almost double that of our nearest competititor. The unique sheave design has 8 gripping faces which directly resist loaded line movement. Traditional designs have an angled resistance to line movement.  Our Generation 2 design has straight resistance faces which both distribute the load and minimise rope wear. These faces are offset from the radial line, to draw the rope down into the gripping area when under load. The ratchet mechanism engages when load is applied, but switches off when it's released. This lets the sheet run out smoothly and freely-great for rapid easing of the sheet and for gybing asymmetric spinnakers. Smooth easing of sheets With auto models the sheet runs out smoothly and freely as soon as the ratchet mechanism disengages. When engaged, and with manual models, the sheave cross - hole geometry eliminates the 'shuddering' ease-out that you can expect from traditional v-groove ratchet blocks. Low profile stand-up kit allows  0° or 90° alignment Stand-up kits feature a clatter-free rubber boot.  You can attach the Dyneema® link so that the block is aligned with the stand-up base or across it.  It's a neat low-profile solution which allows full articulation. FEATURES Up to 14:1 holding power - highest available! Smooth easing of sheets Fully Automatic load sensing ratchet engagement Swivel shackle head for unlimited block rotation. Stainless steel shackle head and compatibility with sharp fixing points. Sheave Ø 55 mm Max. Rope Ø 10 mm Max. Cable Ø - mm Pin Ø - mm M.W.L. 250 kg B. L. 750 kg Weight 78 g