Holder Wire, the black and red two-wire design is great for easy soldering and connecting.Can receive the voltage 3.7V, 7.4V, 11.1V, 14.8V DC supply.The battery holder is fixed by a stainless steel spring. It is very convenient to install and replace the battery, and it is not easy to damage other parts. case compatible with for Ardu Ino board microcontrollers, LED projects, toys, also replaces broken battery holders for many electronic devices. holder bundle with wire is suitable for home improvement and maintenance of all kinds of DC equipment, with screw hole on the bottom and wire pre-installed, it is easy to use.Specifications: casePerfect for use in electronics and small hobby projects.Battery type: for 1/2/3/4 x 3.7 V (battery is not included). Note: Please do not use this battery box, only use it for 1/2/3/4 x 3.7V output. Please do not connect the positive and negative directly. When connected, the cable will get hot.Material:plasticcolour:blackPackage Contents:4 * holder case single slot4 * holder housing 2 slots2 * holder housing 3 slot2 * holder housing 4 slotsOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.