Genuine Pentax lithium ion rechargeable battery pack as used in the Pentax 645D, K-3, K-3 II K-5, K-5 II, K-5 IIs and K-7 digital slr cameras. 7.2v 1860mAh capacity. Lithium-ion technology so there is no memory effect, you can recharge it at any point without having to discharge it first.