Yes this will be compatible with your glock 19x magazine
We have not tested fitment with the Overwatch Precision magwell and cannot guarantee fitment.
The Killer Innovations Velocity Glock 19 Magazine Extension will not work for a Glock 26 or Glock 27.
Yes, the Killer Innovations Velocity Glock 19 Magazine Extension will work with a Shadow Systems MR920 as long as you use Glock magazines.
No, the manufacturer states the Killer Innovations Velocity Glock 19 Magazine Extension is not compatible with Glock PMAGS.
The Glock 45 and Glock 19x use Glock 17 frames. This Killer Innovations Velocity Glock 19 Magazine Extension is for Glock 19's which will also fit the 23, and 32. The Glock 17 Velocity magazine extension is stated to fit only the 17, 22, 24, 31, 34, and 35. The Glock 45 is not listed as compatible and I am assuming it has to do with the flared magwell of the Glock 45. I would recommend reaching out to the manufacturer confirmation.
Yes this will be compatible with your Gen 3, 15 Round Mag
No, these are for the Glock magazines.
No, Killer Innovations makes a mag extension specifically for the G17 mags.
Yes, this will work with the Zevtech magwells.