I am not a fan of conversion kits. Its a great concept, but in practice you wind up with a bunch of parts that can get lost when you need them. And a conversion kit often costs almost as much as a new gun. I’d rather have the second complete gun.
It’s a complete slide and magazine. Very high quality. Had one, but sold it to my BIL.
I have a Glock 17 22lr and a chipita m4 22lr AR upper both slide directly onto the corresponding platform and function flawlessly with 40gr round nose CCIs. The reason for the conversion kits is not only cost you are training with the actual firearm the trigger pull sight radius is identical to the full power round. The AR upper even weighs the same I had that weapon to people all the time and they can’t tell the difference from a full power Ar till they pull the trigger. The mags are fullsized AR mags as well. The G17 upper is a few ounces lighter but functionally identical to a full power G17. Train like you fight and fight loke you train.
4 cents a trigger pull vs 25 and 45 for 9mm and 556 unless you reload which I do but even with reloads 4 cents per round is not reachable, the primers alone are 1 or 2 cents and FMJ bullet a minimum of 10c for 9mm and 15 for 556. It’s nearly impossible for a home loader to beat cast lead 40gr in a disposable brass case made by the billions at the economics of scale.