29mm Carbo Clew Block Assembly from HARKEN
From the folks who invented ball bearing blocks, this line of blocks boasts an excellent strength-to-weight ratio. 29mm doubles and triples feature a U-lock to hold the swivel in the front or side position, or allow it to spin freely. Use the 40mm blocks for jib and mainsheet systems on high-performance dinghies, and for high-load control lines on small keelboats. The 57mm blocks have an enormous working range that makes them ideal for main and jib sheets, spinnaker halyards and control lines.

60mm Racing Fiddle Block with Becket & Cleat, 882lb. SWL, 12.4oz. from LEWMAR
For chafe-free, low-friction tackles. Sheave: Anodized aluminum alloy . Ball Bearings: Delrin® . Sheave Size: 2-3/8" (60mm) & 1-5/8" (40mm) . Line Dia. : 3/8" max. . Cheek Material/Finish: Anodized aluminum alloy . Shackle/Strap Type: Swivel with three-way locking, drilled-out head . Cleat: Model with cleat: adjustable arm, aluminum cam cleat .

Hi-Load Ti-Lite Car, Torlon Bearings, 850lb. SWL from HARKEN
These lightweight, solid aluminum and compact captive ball (CB) travelers are built to handle very high loads. Captive ball bearings let you roll the cars on and off the track without using a ball loader. Boat Size: Dinghies, multihulls, to small offshore boats. Material: One-piece solid aluminum . Shackle: Pivoting toggle models—fasten control blocks directly to post without needing a shackle. Sheave: Fixed sheave models—mainsheet loads 40° or less from vertical.

Spinnaker Pole Car, Track #2720, 900sq.ft. Max. Sail Area, 1125lb. SWL from HARKEN
Now with captive ball bearings, which eliminates the need for a ball-bearing loader during installation or removal from track. These cars run freely, fit low-beam traveler track and are easy to adjust under any load.

57mm Black Magic AirBlock, High-Load Strap Head with Becket, 2,500lb. SWL, 3.6oz. from HARKEN
Strong, lightweight aluminum blocks for offshore boats Used for sheets, halyards, running backstays and control lines on offshore boats, these strong, lightweight blocks are made of sculpted aluminum with Torlon rollers and carbon black balls for strength and UV protection. Cheek Material/Finish: 6160-T6 Hardkote anodized aluminum . Sheave Size: 57mm (2-1/4") . Construction: Three fasteners for quick disassembly. Plastic isolators separate dissimilar metals. Three-way head system.

Large Dinghy Snatch Block, 9/16" Line Dia., 40mm Sheave Dia., 1300 SWL from HOLT ALLEN
Glass-filled nylon cheeks with 316 stainless straps increase working efficiency more than 50% with minimal weight increase. Stainless ball bearings in a polypropylene cassette. For spinnaker sheet, jib sheet turning blocks, etc. Cheek Material/Finish: Glass filled nylon. Ball Bearing: Stainless ball bearings. Opening: Hinged cheek/axle.