This is the genuine Nikon battery cover BL-6. It's a battery chamber cover used in combination with the Li-ion rechargeable battery EN-EL18 series. Compatible with Li-ion rechargeable batteries EN-EL18d, EN-EL18c, EN-EL18b, EN-EL18a, and EN-EL18. Compatible with Nikon cameras D4, D4s, D5, and D6. This is a used item with signs of use, but it has been tested and is a great value. Unlike the battery itself, it's just a cover, so there should be no problem even if it's used.