Nockturnal’s Lighted Launchpad Universal Crossbow Nocks offer outstanding reliability in the worst possible conditions. They provide a vital indication of where your arrow hit the animal, and also aid in locating your arrow if you miss. The Launchpad Universal Crossbow Nocks are bowstring activated to keep operation simple and intuitive, and are both water and weather proof. Available in red or green, the Launchpad Universal Crossbow Nocks have an extended runtime of 20+ hours and fits nearly all crossbow arrow models. Features: Durable & Long-Lasting Integrated, one-piece aluminum housing protects battery and LED during high-speed flight and impact. Custom-Fit Micro-Adjustability, adjustable barrel end is easy to install and provides a reliable performance fit. One Size Fits nearly all crossbolt brands and models (comes with 2nd Grey Collet).Includes reusable c-clip to prevent lighting during storage. Easy & Reliable On/Off Indexed nock end provides added safety and an easy ON/OFF design. Available in Red or GreenEach nock in this package weighs approximately 30 grains3 per package Nockturnal Launchpad Crossbow Nock Green 3pk NT-775