Lumenok X Nock (3-Pack), Green The Lumenok is a Green lighted arrow nock used for shot placement recognition & arrow retrieval. Lumenok X lighted arrow nock fits .204" ID carbon and aluminum shafts. Each Lumenok is equipped with a replaceable battery (Lumenok part # RB). Shot placement recognition and arrow retrieval. Easily replaceable battery Fitment guide is available under product details.