SPECIFICATIONS 1.Fits any bolt with inside diameter 6.2MM, 2.Turn on and off easily 3.same plastic color as the light 4.Weighs only 20 grains 5.Battery life: up to 20 hours 6.Color :green.red. 7.Package : 6/12pcs light nocks 8.The luminous light makes it easier to see 9.Lightweight and precision-balanced for superior accuracy...