The Strongest Link in Your Chain The strongest link – Mantus swivel is stronger than its corresponding Grade 40 chain. (WLL is 1/5 UBS) Integrated shackle design completely eliminates side loading making this the safest swivel on the market. The pin on the chain side of the swivel is the strength limiting part since the geometry of the chain determines the pin size. Mantus swivel is the first to feature an oblong pin to maximizes the pin strength, with the aid of computer modeling and physical testing we truly created a swivel that is the strongest link. Note the innovative shackle bolt design – no shackle dog! This slim hex head design (with holes for safety wire) offers a slimmer profile making it easier for translating through your bow roller. 316 L Stainless Steel, Precision Cast and Electro-Polished Body Pin made from Duplex Stainless Steel and is mechanically polished and electro-polished.