Best $24 I ever spent. I had some problems with a dead trigger on my new V1 M&P 45 full size. Sent it back to S&W, but they found nothing wrong. I installed all the M*Carbo springs, polished the trigger bar and striker, sear, and even the striker safety per the video. Range finally opened up, and took a couple hundred rounds of the same ammo I had trouble with before. Cheap Remington FMJ ammo, but no problems this time at all. Accuracy is a lot better, for me at least, with a reduced trigger pull. I also replaced my trigger in my new CZ P10F at the same time (HB Industries), and I will tell you it's a lot easier to do than a Smith & Wesson, and it's a tack driver to boot! You may give M*Carbo a try if you want a better trigger for a LOT less money than others.