The Pro MAg magazine is compatible with your Glock 17/19/26. It is constructed of DuPont Zytel polymer with full length internal insert, injection molded mag follower and mag spring formed from chrome silicone wire. Made in the USA.
Specifications:

Caliber	9mm Luger
Capacity	17
Finish	Black
Model	Replacement Magazine
Material	Polymer
Type	Detachable
Model Fit	G17/19/26
Brand Fit	Glock
Max Capacity	17