Bohning's Smooth Release Pin Nock was redesigned in 2019 to fit a broader range of pin sizes - redesigned nocks are easily identified as they are marked with the Bohning logo. The Smooth Release Pin Nock features a raised index, short ears and a smooth throat for a clean release. Each nock weighs an average of 5.0 grains (324 mg). Its .120" (3.05mm) throat size is designed to fit larger diameter bowstrings typically used by compound shooters. Not sure which Bohning Pin Nock you have? The Smooth Release Pin Nock is marked with the letter "M" for easy identification. Tech tip: for easier insertion and indexing, apply a small amount of Bohning's Tex-Tite or Seal-Tite wax to the pin. NOT ALL BRANDS OF NOCKS ARE CREATED EQUAL At Bohning, every nock style must pass the following steps before introduction to the market: 1. Computer simulations identify potential weak points. 2. Destructive testing methods expose possible design flaws or material defects. 3. Accelerated life cycle testing using a custom-built bow is performed at kinetic energy levels exceeding 110 ft-lbs (nearly twice that of most hunting bows). A single nock must withstand over 1000 shots or it goes back to step 1. Proudly manufactured at the Bohning Factory in Lake City, Michigan, United States.