Overview: The Half Moon Crossbow Nock is the perfect replacement nock for your crossbow bolts. Constructed from durable, impact resistant polycarbonate material and designed to fit Standard 14"-20" Crossbow bolts, including Man Kung Highlights: Weight: 0. 06oz. Length: 0. 73in. Thickness: 1. 92mm Package Contents: 30 x Crossbow Arrow Nocks.