Ronstan Series 55 Ratchet Orbit Fiddle Block, Auto/Manual, 21:1

Experience superior control and efficiency on your sailboat with the Ronstan Series 55 Ratchet Orbit Fiddle Block. Engineered for optimal performance, this block boasts Ronstan's highest available holding power, ensuring precise sheet handling and quick adjustments for any sailing condition. Its unique auto and manual engagement modes offer unparalleled versatility, adapting to your specific needs whether you're racing or cruising. Upgrade your rigging today for a smoother, more responsive sailing experience.

• Exceptional Holding Power: Features up to 21:1 holding power, achieved through Generation 2 of Ronstan's patented sheave cross-hole geometry with 12 gripping faces, providing superior load resistance and minimizing rope wear.
• Versatile Engagement Modes: Switch between auto-ratchet mode for smooth, free easing of sheets (ideal for gybing asymmetric spinnakers) and manual mode for consistent, engaged cleating, offering flexibility unique to Ronstan blocks.
• Ultra-Lightweight Construction: Designed with all-composite reinforced polymer materials and a Dyneema® rope link head, resulting in the highest strength-to-weight ratio in its class for reduced ineffective mass.
• Low Friction 2-Stage Bearing System: Utilizes high compression strength carbon black Acetal ball bearings and a secondary full-contact bearing to ensure minimal friction across the full working load range.
• Durable Materials: Constructed with an anodized aluminum sheave, toughened glass fiber reinforced Nylon frame and cheeks, and a UV stabilized, multi-strand SK75 Dyneema® rope link, all complemented by a grade 316 stainless steel swivel shackle head for corrosion resistance and longevity.
• Maximum Line Size: Accommodates lines up to 3/8 inch (10mm), suitable for a wide range of sailing applications.
• High Working Load: Rated for a maximum working load of 550 lbs (250 kg), providing reliable performance under significant tension.
• Impressive Breaking Load: Offers a breaking load of 1650 lbs (750 kg) for enhanced safety and durability.
• Compact & Lightweight: Weighs only 3.9 oz (112 g), contributing to a low-profile setup without compromising strength.

• Mainsheet systems on dinghies, sportsboats, and small keelboats up to 9m (30ft).
• Spinnaker sheets on dinghies, sportsboats, and small keelboats up to 9m (30ft).
• Halyard, vang, and backstay applications on boats up to 8m (26ft).
• Control line applications on larger yachts.