Ronstan RF51510 Series 50 Fiddle Block with Becket

The Ronstan Series 50 All Purpose Fiddle Block with Becket is engineered for mainsheet, halyard, and control line applications on cruising and racing sailboats up to 33 feet. This double-sheave fiddle configuration provides excellent mechanical advantage while maintaining a compact footprint, making it ideal for fine-tune mainsheet tackles, cunninghams, backstays, and other purchase systems.

Key Features:

• Exceptionally high working loads with low maintenance and extended service life
• Self-lubricating Acetal polymer sheaves running on polished stainless steel races for smooth operation under both dynamic and static loads
• Captive Lock™ universal head can be fixed in two planes or left free to swivel as needed
• Slotted pin shackle design eliminates fouled lines and simplifies attachment
• Snap-fit removable becket pin allows line splicing before installation and locks into position without clevis pins, split rings, or tools

Construction:

• Grade 316 stainless steel load strap for maximum strength and corrosion resistance
• Impact and UV-resistant, fiber-reinforced Nylon cheeks for durability in harsh marine environments
• Polished stainless steel races ensure smooth, low-friction operation

Applications: Mainsheet and halyard systems, vang and spinnaker control lines, backstay adjusters, cunningham controls, and general-purpose purchase systems on sailboats to 10 meters (33 feet).

Replacement Parts: RF51010 Replacement Becket Pin, RF150 Shackle