The Shield Arms Z9 is a 9-round steel magazine for the Glock 43 - same external length as the OEM 6-round magazine with a pinky extension, but holding three additional rounds in the same on-belt footprint. The steel body keeps wall thickness thin compared to polymer, which is how Shield Arms gets the extra capacity without growing the magazine. Specs: Caliber: 9mm Capacity: 9 rounds Body: steel with Powercron cationic epoxy coating (corrosion-resistant) Compatible: Glock 43 (NOT 43X - see Shield Arms S15 for 43X) Drop-free with the OEM magazine release; pairs cleanly with extended releases Break-in: Steel mags benefit from a few load/unload cycles at full capacity to settle the spring. Load to nine, leave overnight, then run a magazine of full-power 124gr through the gun to confirm last-round bolt lock and clean ejection. If you sweat heavily or carry in a humid environment, wipe the body with a light coat of CLP every couple weeks - the Powercron finish handles it, but bare contact points appreciate it. DISCLAIMER: "GLOCK" is a federally registered trademark of GLOCK, Inc. and is one of many trademarks owned by GLOCK, Inc. and GLOCK Ges.m.b.H. Neither 3CR Tactical 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 additional genuine GLOCK, Inc. and GLOCK Ges.m.b.H products and parts visit www.glock.com.