This is a factory original, drop-free magazine for your Glock Gen 5. Glock magazines have a hardened steel insert encased in high tech polymer. This polymer coating protects the magazine and prevents deformation, even when dropped from a great height. Notes:These Glock magazines are compatible with previous and current generation Glock pistols except the Glock 19x. Flush-fit (non-extended) magazines will not interface with the frame lip on the Glock 19x. Gen 4 magazines do seat properly with the 19x.Glock magazines have very stiff springs when new and may be extremely difficult to load to full capacity. It may be necessary to use a Glock magazine loader (generally included in the Glock case with the handgun) to load the magazine to capacity or near capacity. If the last round appears impossible to load, for example if the magazine should hold 15 rounds and it will only accept 14, leave it loaded with 14 rounds for several days to allow the spring's tension to decrease. After a shor...