Ronstan Series 40 Orbit BB Quad Block w/Swivel Shackle. They offer class-leading dynamic and static load ratings the highest available in this size of performance blocks. Lightweight and strong toughened glass fiber reinforced nylon cheeks replace stainless steel straps used in traditional utility blocks - the perfect balance of performance and reliability. As well as traditional single swivel blocks the range includes single and double sheave lashing or soft attachment options through to multiple sheave blocks including those with quad and quin sheaves. The range is highly versatile allowing a multitude of possible systems right up to a 12:1 purchase mainsheet system for off-the-beach performance catamarans. Series 40 Orbit Blocks are fitted with their carbon-reinforced C-Cleat for secure rope holding with low entry and exit efforts and fairleads for fast action from any angle. Cleat arms are made from stainless steel and adjustable for setting your preferred cleating angle. Ball Bearing versions incorporate their 2-stage bearing system using ball bearings to minimize friction and a secondary full-contact bearing to maintain low friction across the full working load range. High Load versions are designed specifically for any application where high dynamic or static loads are expected. They feature a high-strength grade 2205 stainless steel sheave & hub together with a triple bearing race to maintain low friction at very high loads. Package Contents: Ronstan Series 40 Orbit BB Quad Block Ronstan RF48400: Series 40 Orbit BB Quad Block w/Swivel Shackle