Item Type: 18650 Battery Holder Box
Type: 2 slot
Size: 77.1 x 39.80 x 14.90mm
Material: PA66, gold plated copper heat treatment
Color: black UL-94V0
Fit for: 18650 3.7V battery
Simple DIY recharge power supply.
You could use this case with your own battery to form power supply system.