GLOCK® +10% EXTRA POWER MAGAZINE SPRINGS FOR GLOCK® 17/17L/20/22 Increased pressure stabilizes the follower and improves feeding, especially on high-capacity magazines. Glock®- Hi-Cap 17 fits 17, 17L, 20 (15-rd), 22, 31 (15-rd), 34 (17- and 19-rd), and 35 (15-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 pistols, parts, or components. For genuine GLOCK, Inc. and GLOCK Ges.m.b.H. products and parts visit www.glock.com.