Each GLOCK magazine is constructed from a hardened steel insert encased in high tech polymer to protect the magazine and prevent deformation, even when dropped from a great height.
GLOCK, OEM Magazine, 10MM, 10 Rounds, For GLOCK 20, Cardboard Style Packaging, polymer, Black
Pearce Grip, Grip Extension, Fits Glock 29/20/21/40/41 High Capacity Magazines, Black
ETS magazines are made from advanced polymers that provide extreme impact resistance, so they won't crack or break when dropped.