For protecting a valuable select-fire receiver, or even a semi-auto receiver that has seen a high volume of fire, the KNS non-rotating trigger and hammer pins are a must. Anti-creep retainers keep the pins from constantly rotating during extended firing sessions and weakening the receiver walls. Modification II pins retain the popular original "dogbone" look of Generation I pins, with added strength for longevity. Not compatible with Jewell match triggers.