" through what appears to be clever engineering, only the loaded portion of the "floating" aluminum sheave comes in contact with the ball-bearing arrangement. This makes for smooth trimming and blazingly fast sheet runs at the weather mark and late dips" From Dave Reed's Sailing World Review . Read the Sailing World Review of this Block These are easy to use as the ratchet function engages automatically when there is enough breeze. The ratchet auto disengages in lighter air or when easing for the run. Unlike competitors this can also be switched on and off. Now these auto/manual ratchet blocks come with a stainless steel swivel shackle for ultimate durability. Sheave Diam. 2 5/32 in. Max. Rope Diam. 3/8" / 10mm Max. Working Load 550 lb Breaking Load 1430 lb Weight 2.8 oz Read a review of this block Availability: Usually ships the next business day. RF56100Regular price: $73.95Sale price: $62.99 Harken Stand up Spring for Dinghy Main Sheet Blocks2" X 7/8" Spring works for the Main sheet blocks on the Laser®, Sunfish®, Otimist and many other small dinghy main sheet blocks. Availability: Usually ships the next business day. H071Regular price: $0.95Sale price: $0.81 Harken Stand Up Boot Made of durable flexible PVC, stand-up boots hold blocks up without snagging lines. The 370 fits up to 75 mm blocks. Availability: Usually ships the next business day. H370Regular price: $11.50Sale price: $9.78 Due to the wide variety of the size and weight of our items we will charge the actual cost of shipping in a separate charge on all orders. Please email us for a shipping cost estimate. Shipments outside the USA may have add on fees and duties by your own government. Sailing can be green! See our recycle your old sail offer Send us email