These extensions are ergonomically shaped for better insertion - and feature finger grooves enabling the magazine to be stripped from the handgun if needed. Machined from 6061 TB aluminum billet Type 2 hardcoat anodize finish for abrasion and corrosion restistance Torx head screw and washer for retention Designed and made in the U.S.A. +5 9mm Capacity +4 .40 Capacity Black DISCLAIMER: GLOCK is a federally registered trademark of GLOCK, Inc. and is one of many trademarks owned by GLOCK, Inc. or GLOCK Ges.mbH. Neither Sportsmans Outdoor Superstore nor this site are affiliated in any manner with, or otherwise endorsed by, GLOCK, Inc. or GLOCK Ges.mbH. 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.mbH products and parts visit www.glock.com.