The workhorse of the Harken line, the entire range of Black Magic AirBlocks has been redesigned with a sleek new look.
Their unique, performance-packed engineering remains exactly the same.
Used on offshore boats, these strong, lightweight blocks feature aluminum cheeks, and free-rolling, high-load Torlon roller bearings for a high strength-to weight ratio.
Use them for sail controls that see lots of action mainsheet, runner, halyard and spinnaker systems.

Easy Maintenance
AirBlocks are easy to clean and service.
They have few parts and no loose balls or rollers to misplace.
Unlike blocks that are riveted, fasteners allow quick disassembly with a single hex wrench.

Low Friction Caged Bearings
Roller bearings are housed in a unique center cage that keeps them separated and parallel for lower friction.
Dirt and sand falls out between the rollers.
Captive Delrin ball bearings carry any sideloads.

Strong, lightweight sideplates and sheaves
6061-T6 aluminum sideplates are sculpted to remove excess weight.
Thin-profile, deep groove aluminum sheaves have radiused edges to protect high-tech lines.

Long-lasting protective finish
Sheaves and sideplates are deep-saturation Hard Lube-anodized forstrength and durability.
UV stabilized, and PTFE-impregnated for maximum protection and a smooth, slippery surface.

30% lighter, 60% higher working load than equivalent sized ball bearing blocks
High- and low-load versions
Breaking load is 2 times safe working load
Sheave diameter: 3.94" (100 mm)
Dissimilar metals isolated to prevent corrosion - plastic isolators under all fastener heads and headposts
Three-way head - set screw locks shackle in front or side positions, or lets block swivel to keep line from twisting