Installation is quick and no adjustments are necessary, 100 percent true drop-in trigger. The trigger module installs using your rifle's original hammer/trigger pins and the proprietary design eliminates pin rotation and walkout. Since it was founded in 1946, Timney Manufacturing has built a reputation based on the quality of its products. Because of the precision machining and workmanship that goes into each and every Timney product they are often referred to as "The World's Finest Triggers" and they are used exclusively by some of the world's best custom gun manufactures. Made in the USA. Factory 3 lb pull Drop-In Trigger module installs using your rifle's original hammer/trigger pins and the proprietary design eliminates pin rotation and walkout If you have a polymer lower, TImney recommends putting a small thin piece of aluminum underneath the trigger to protect the polymer lower Solid, straight shoe design