Free Bluetooth, APP for Phone-Xiaoxiang BMSParameters can be Read at any time(English Version)Support UART communication, Used to Turn on Equalized Voltage and Pressure Difference Adjustment, online upgradeUsed for Small Energy Storage Battery, Street Lamp, 12V Lead-Acid Replacement Lithium BatteryColour:As shownMaterial:PC+MetalPackage Contents:1 x 20A Bluetooth BMS/1 x 50A Bluetooth BMSOnly the above package content, other products are not included.Note: Light shooting 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.