Harken 12:1 Mainsheet Carbo Boom Block 

Murrays Part# 56-9966

Harken 57mm triple fiddle block with swivel used for 12:1 mainsheet systems on beach cats.

Low-friction Carbo AirBlocks® are lightweight, strong, reliable and affordable. These small, compact blocks have very high working loads for safe, easy trimming.

Specifications:

• Sheave Diameter: 2-1/4"
• Length: 6"
• Maximum Line Diameter: 7/16"
• Maximum Working Load: 2380 lb.
• Breaking Strength: 5000 lb.
• Weight: 11.15 oz.

Harken Part# HSB379