Gold Tip Accu-Bushing GTO Nock Kinetic 400-600 12 pk.. Prevents the arrow shaft from being damaged by nock end impact. Specifications for Gold Tip Accu Bushing - .204 Series - .166 Nock: Manufacturer: Gold Tip Inner Diameter: 0.166 in Color: Brass Quantity: 12 Fabric/Material: Brass Weight: 7.3 grain Features of Gold Tip Accu Bushing - .204 Series - .166 Nock Weight: 7.3 gr Fits GTO nock (.166) Large fits 2 & 3 spines Package Contents: Gold Tip Accu Bushing - .204 Series - .166 Nock Designed to use GTO (.166) nocks in Kinetic arrows. Features/Specifications: Weight: 7.3 grFits GTO nock (.166)Small fits 34 4 5 spines