Check the listing for details. 30 Pack Archery Arrows Nocks 4.2mm Plastic Insert Arrow Nock Black. Color: Black, Condition: New. Listed at 13.25 USD. Plastic archery arrow nocks can allow the nock to leave the string smoothly, reducing the damage to the arrow, and prolonging the life of the arrow, suitable for compound bows and recurve bows.Specification Color: BlackMaterial: PlasticSize: 6.3 x 28.5 mm / 0.25 x 1.12 Inch (W x L)Outer Diameter: 4.2 mm / 0.16 InchPacking List: 30 x Arrow NocksAdvantageThe arrow tails are made of durable plastic material with a smooth surface, light and portable, and easy to remove. The bright colors ensure that they can be easily spotted in the grass or forest. In addition, the plastic nock replacement has large and deep grooves that can well fix the position of the bowstring.InstructionSmooth press-fit nocks, no gluing required, easy to install.Note: Please pay attention to the size before purchasing.