Bohning Smooth Release Insert Nock Blue 12 pk. 246? ID. It is engineered using a single click design to give you the ultimate accuracy and weighs 7.0 grains. Features of Bohning Smooth Release Insert Nock: Designed for target archers Fits Uni-bushing or standard sized arrows with .246" ID Single click design for accuracy Weighs 7.0 grains Package Contents: Bohning Smooth Release Insert Nock Bohning 401033EB: Smooth Release Insert Nock Blue 12 pk