4mm Shallow Bow ShackleForged stainless steel shackles are polished to a high luster and are stamped with the screw pin diameter.. Bow shackles are best for multidirectional loads. Shallow bow shackles are proportionally wider for their length than regular bow shackles.Specifications:. Shackle pin: 4mm / 5/32in. Weight: 8.5g / 0.3oz. Maximum working load: 367kg / 810lb. Breaking load: 735kg / 1620lb