Inserts: 
2011 - Fits 2011 & Double Stack Magazines - P320, M&P, VP9, ETC
Glock - Fits Glock 9/40/45
Glock19 magazines are the shortest  you want to use in these pouches. Will not work for Glock26 or similer magazines they too short in height.
 
Lidded KYWI Pouch meant for Glock 19 and Glock 17 sized magazines.
 
Glock 19X sized 19rd magazines are around the max length magazine the lids will work with.
 
Please note that if you buy this pouch and hear random voices at night, its most likely your lidded KYWI pouch wondering why it exists. Please secure all razor blades and knives.
 
*esstac will be phasing out the PALS webbing on the rear of Kywi pouches with Brookwood Laminate Squadron laser cut PALS backers. Squadron is currently in use with many of their current pouches. 
 
During the transition, orders may contain pouches with webbing, the new laser cut backer, or a mix of both.
 
There is no guarantee of which version you will receive.