Improves tactile trigger reset and acts as a failsafe for trigger return spring breakage in S&W M&P 9mm, .357 Sig, and .40 S&W models without a thumb safety, Magazine Disconnect, or Internal Locking System.
Not compatible with the VTAC variant due to a different sear housing block configuration.
Made in the USA, the mechanism is precision machined and heat treated for durability and longevity.