Coreless battery assembly designed for experienced personnel familiar with battery performance and assembly techniques. Requires 5/10 cores of 18650 power lithium batteries for assembly, not included in the product. No after-sales service provided; purchase with caution if you have objections. Preparation requires tools such as spot welding machines, soldering irons, multimeters, and suitable chargers. This product is a coreless battery assembly. It is intended for use in the repair and assembly of battery packs that it is only suitable for personnel who are familiar with battery performance and have practical experience in battery assembly. This product does not have after-sales service, it is just a set of comits without batteries. You need to use your own 5/10 cores of 18650 power lithium batteries to assemble a battery pack. Please purchase with caution; if you have any objections, please do not place an order. Preparation before assembly: You must have 18650 li-ion batteries and the tools such as spot welding machines, soldering irons, multimeters, and suitable chargers, etc. Color: As Shown Material: ABS+PC Package Contents: 1*set of accessories Only the above package content, other products are not included. Note: Light reflection 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.