TenPoint Crossbow Technologies Alpha-Nock HPX Yellow. These nocks feature a unique Nock Retention Groove that audibly snaps into place giving you confidence that your arrow is properly seated. Built with an HP Aluminum Bushing for increased durability and a deep bowstring groove for better nock travel they ensure straight accurate shots while reducing string wear. Whether you're a seasoned hunter or a target shooting enthusiast these nocks offer the reliability and performance upgrade needed for your TenPoint crossbow. Specifications for TenPoint Crossbow Technologies Alpha-Nock HPX: Manufacturer: TenPoint Crossbow Technologies Nock Type: Alpha-Nock HPX Quantity: 12 Pack Package Contents: TenPoint Crossbow Technologies Alpha-Nock HPX TenPoint Crossbow Technologies HEA-364.12Y: Alpha-Nock HPX Yellow