The Lumenok (lighted arrow nock) is fast becoming the most popular lighted nock on the market. The Lumenok is a lighted uni-nock and adds only 22 grains of weight to your arrow. Simply remove your nock and put in the Lumenok and you are ready to go. Lumenok X Fits .205 ID shafts. Trophy Ridge shafts: Crush, Blast Hailfire, Wrath. Easton: Axis, AC Superslim, Full Metal Jacket. Beman: MFX Black Max carbon.