GLOCKA(R) +10% EXTRA POWER MAGAZINE SPRINGS FOR GLOCKA(R) 19/21/23/ Increased pressure stabilizes the follower and improves feeding, especially on high-capacity magazines. GlockA(R) Hi-Cap 19 fits 19 (15- and 17-rd), 21 (10- and 13-rd), 23 (10- and 13-rd), 26, 27, 29, 30, 33 (10-rd). DISCLAIMER: "GLOCK" is a federally registered trademark of GLOCK, Inc. and is one of many trademarks owned by GLOCK, Inc. or GLOCK Ges.m.b.H. Neither Brownells nor this site are affiliated in any manner with, or otherwise endorsed by, GLOCK, Inc. or GLOCK Ges.m.b.H. The use of "GLOCK" on this page is merely to advertise the sale of GLOCK Mfg: Wolff