Ronstan RF51100 Series 50 All-Purpose Single Block with Shackle 50mm

The Ronstan Series 50 All-Purpose Single Block delivers the smooth, efficient performance that dinghy and small keelboat sailors need for precise sail control. This 50mm block is engineered to provide clear tactile feedback through hand-held control lines, allowing sailors to detect subtle wind changes and adjust sails with confidence.

Key Features:

• 50mm self-lubricating, UV-stable acetal sheave runs smoothly on 316 stainless steel bearing for low friction operation
• Fiber-reinforced nylon cheeks with 316 stainless steel load straps provide exceptional strength-to-weight ratio
• Captive lock system secures swivel at 0° or 90°, or allows free rotation as needed
• Included shackle features low-profile pin head to prevent snagging on smaller lines
• Sliding acetal bearing on stainless steel race handles high static and dynamic loads
• Compatible with 1/2" (12mm) line with 3/16" shackle pin diameter

Ideal Applications:

• Halyard tuning systems and Cunninghams
• Dinghy and small keelboat sheets
• Backstay systems on dinghies and smaller keelboats
• Boom vangs and cascade systems

Designed for moderate to high-load applications where responsiveness and durability matter, the RF51100 combines lightweight construction with robust engineering to deliver reliable performance season after season.