Our new Glock Mag Extension is made of High Grade/Impact Resistant Polymer with a proprietary base plate system allowing for a much easier installation process. Shipped with a new spring, it allows for +5 rounds in the Glock 17 magazine, +4 rounds in the Glock 19 magazine, +4 in Glock 22 magazines, and +3 on magazines for the Glock 23.
