The HK USP Compact 9mm 13-round magazine is a factory-made magazine designed specifically for use with the Heckler & Koch USP Compact pistol chambered in 9mm Parabellum (9x19mm). Here are some key details about this magazine:

1. Caliber Compatibility: The magazine is designed for use with the HK USP Compact pistol, which is chambered in 9mm Parabellum. This caliber is widely used for handguns and is known for its manageable recoil and versatility.
2. Capacity: The magazine has a standard capacity of 13 rounds. This is the typical magazine capacity for the USP Compact chambered in 9mm and provides a balance between ammunition capacity and compactness.
3. Construction: HK factory magazines are known for their quality construction. They are typically made with a combination of steel and polymer for the magazine body and baseplate. This construction ensures durability and reliable feeding.
4. Compatibility: The magazine is designed specifically for the HK USP Compact in 9mm. It may not be compatible with other firearms or USP models chambered in different calibers.
5. Availability: Factory magazines for HK pistols are generally available through reputable firearms retailers or distributors that specialize in HK firearms and accessories.
6. Legal Considerations: Always be aware of and comply with local, state, and federal laws and regulations regarding magazine capacity and firearm ownership. Magazine capacity restrictions can vary by location, so it’s essential to understand and adhere to local laws.

The HK USP Compact is a reliable and popular choice for concealed carry, law enforcement, and self-defense. The availability of factory magazines with standard capacities, such as this 13-round magazine, ensures that users have reliable and compliant options for their USP Compact pistols.