Mantus swivel is stronger than its corresponding Grade 40 chain. 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. This slim hex head bolt design (with holes for safety wire) offers a slimmer profile making it easier for translating through your bow roller.316 L Stainless steel constructionPrecision casted and electro polished finish5/16 to 3/8" size