Easy to Install: This user-friendly board has a simple installation process, making it an ideal choice for professionals and DIY enthusiasts. Performance Optimization: This 21V balanced protection board is designed specifically for power tools to that your tools run efficiently. It provides a powerful charging and protection solution to extend the life and performance of your battery. Advanced Safety Mechanism: This protection board is equipped with multiple safety features to prevent overcharging, short circuiting and over-discharging, ensuring the safety of your power tools and batteries under various working conditions. and Reliable: This module ensures durability and reliability for continuous use. It is an essential accessory for power tools and helps keep your power tools at their best performance. Color: As Shown Material: PCB Package Contents: 1 * Battery Protection Board 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.