SCHAEFER 51mm 5 Series Double Block - Swivel, 504-25

Schaefer Double Aluminum Block allows for a 4:1 purchase. 

Used extensively for sheet blocks on small- to mid-sized keelboats, and as control line blocks for larger offshore boats. Suitable as mast-base or lead blocks on small- to mid-sized boats. Adaptable universal three-way head. Black anodized aluminum or stainless steel cheeks. Stainless steel straps and posts.
 

Note: Special Order Only

• 3-Way swivel head can be set to swivel 360° or can be locked to avoid twist
• Universal design suits diverse applications and mounting options
• Tough, hard coat-anodized aluminum cheeks 
• Smooth UV resistant, Delrin™ sheave
• Accepts Schaefer "universal" adapters for custom mounting
• High strength-to-weight ratio