ProMag GLKA17 Standard 22rd 45 ACP Compatible w/ Glock 30/21 Black DuPont Zytel Polymer
The Pro MAg magazine is compatible with your Glock 21/30. It is constructed of DuPont Zytel polymer with full length steel internal insert, injection molded mag follower and mag spring formed from chrome silicone wire. Made in the USA.