NP-BASE:
The NP-Base holder clamps to your camera's handle and allows you to independently power a 12V light from a NP battery. The holder has a 12VDC power port and a 1/4-20 thread so you can mount the light.

NP-BH:
The NP-BH mounts directly to your NP box, holding an additional NP battery for powering an on-board light. When used with a NP-L60/L70, the power port can be easily connected to. The holder also has additional mounting screws to allow for piggy-backing or mounting a wireless receiver.