This is an interesting kind of battery holder, usually you'll see ones that are designed for holding like AAA's or something. This battery holder is designed to clip into and hold camcorder batteries. Specifically, the common SONY NP-Fxx series of batteries and compatibles, made with cylindrical LiIon cells and 7.4v nominal output. By clipping a battery in, you can use this holder to plug into any device with a 2.1mm DC jack that wants about 7VDC. Great for robots, Arduino projects, portabilizing gadgets, etc.Comes with just the plastic holder and cable assembly. No...