Fits .246" ID Shafts Directly. If Your arrows have bushings from the factory, those will have to be removed. Please contact us for detailed instructions for that . Weighs 22 grains Each Lumenok is equipped with a replaceable battery (Part No. RBS). The Lumenok lighted arrow nock is activated upon the shot to allow archers to follow the path of their arrow. This model Lumenok provides up to 40 hours of illumination and can be seen from great distances. No moving parts or switches to break. This Lumenok is made using a genuine Burt Coyote nock.