This battery box holder with pin connector, fit for 18650 batteries. With weld leg design, you can easily to put the battery in it. With a cap and on/off switch button Design:Serial Connection Fit for:2x18650 3.7VBattery (Not Included) Rated voltage: DC 7.4V Size:9.3 x 4.2 x 2.2cm (LxWxH) Wire Length:16cm Material:Plastic Color:Black