Durable & Long-Lasting Integrated, one-piece aluminium 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 Green, Each nock in this package weighs approximately 30 grains, 3 per package