Breakthrough Design- Lighted nocks for arrows with switch, turn on automatically when Amazing LED Nock- Very bright, fit for arrows with 6.2mm/.244 inch inside diameter High Visibility- Clear plastic for maximum light transmission,find the quarry and even at night or dawn Long Battery Life- 48and hours of battery life,long lasting but light weight Super Handy- Simple On/Off switch design (without tool),no assemble required Colour: GreenandTransparentandSilver Material: PC Size: 6.2mm Package Contents: 12 x nocks Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.