The Barton TuphBlox Size 4 Swivel Block is built for strength and reliability in demanding marine applications. Designed with a swivel head for increased flexibility and reduced rope twist, this block is ideal for use in dynamic rigging setups. It features a Tufnol sheavean ultra-durable phenolic laminate reinforced with cottonknown for its low weight and high resistance to wear. Stainless steel (316) side plates and brass bearings provide smooth, long-lasting performance in harsh marine conditions.