Sig Sauer MPX Gen 1 Magazine, 9mm, 30rd. This is a bulk packaged item and does not come in the original Sig Sauer package. It is an OEM Sig Sauer product. These are most reliable in the first generation MPX. It is recommended to use the Gen 2 magazines in firearms with keypad rail (those are Gen 2).
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.