Stock up on extra magazines for your MPX. This is a brand new OEM SIg Sauer MPX 9mm 20-Round Magazine. These are direct from Sig and not a third party or some other manufacturer.
This is the Gen2 magazine for guns with a -KM part number which have a Keymod rail. These have a FDE follower. Please check the original magazine that shipped with your MPX. If it has a FDE follower then this is the magazine you need. If you have a black follower you need Part Number: MAG-MPX-9-20. We cannot guarantee 100% reliability when using these magazines in the "Gen 1" MPX.