This is a Black Plastic Storage Box Case for a 2 x 18650 Cell Box, with a Cover and On-Off Switch. This holder has an On-Off switch that can be used to control power to your system. The cover provides protection to the battery. The case box can keep your batteries organized and protected. The holder case is designed with leads for easy to solder and connect. This battery holder case is perfect for devices that need a 7.4V external battery.