This is a Gen 3 27 slide on a Glockstore M1X frame, the M1X is a fuller Grip think Glock 23 grip with a 27 slide or a Glock 19 grip with a Glock 26 slide, photos for reference on size one photo compares to Glock26 other photo is next to 19 ,open to trades as well looking for these Glock models 


Glock 21/21SF 30/30S/ 29/29SF/33/45/17 /19C/19M