This is a wonderful mainsheet block that automatically engages the ratchet when the tension on the line is high enough then auto disengages for easy pay out of the sheet at the windward mark. You can adjust the tension with the included allen wrench. Is your ratchet on or off? That is one less thing to think about on the water! Sheave dia. (in) 2-1/4 Length (in) 4-1/16 Weight (oz) 3.7 Max. line dia. (in) 3/8 Shackle pin dia. (in) 3/16 SWL (lb) 500 Breaking strength (lb) 2000 Holding power w/180 degree wrap 50 lb (23 kg) 10:1 2625Price: $128.45Sale price: $112.95 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. H071Price: $1.75Sale price: $1.49 Harken Spring Cup HSB2$1.49 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. H370Price: $17.85Sale price: $15.95 WE SHIP WORLDWIDE! We charge the actual cost of shipping. You may email us for a shipping cost estimate. Send us email intensitysails(at sign)gmail.com US$10 MINIMUM ORDER