Stock up on extra magazines for your MPX. This is a brand new OEM SIg Sauer MPX 9mm 30-Round Magazine. These are direct from Sig and not a third party or some other manufacturer.
Sig does also offer smaller capacity magazines but they may not be as readily available. This is a bulk packaged item and does not come in the original Sig Sauer package. It is an OEM Sig Sauer product.