Put these parts into a basic Mil Spec Parkerized Springfield 1911. Old trigger had a long take-up, was gritty and had an inconsistent break. Just these parts (and a little stoning of the trigger bar) and the trigger is transformed. Now no creep and crisp break. Every bit as good as my Nighthawk Customs T4, although not as light (I did not want to tune it as light, so made no other changes). The thumb safety required some tuning (too long and contact the sear before fully engaged), but otherwise was "drop-in." Also accidentally ordered two, and requested a return by email. John answered in a few hours said just send it back and he'd take care of it.