This is the new factory BX-trigger for the Ruger 10/22 or Charger pistol. It will fit any 10/22 rifle or charger pistol, even the takedown models! It is a drop-in unit that features a light and crisp 2.5 to 3 lb pull versus the factory 6 to 7 lb pull. You will love it!! It is very easy to install and takes just a few minutes. No gunsmith required!