Car Round Bluetooth Display $ 11.41 Bluetooth version 5.0 Support USB 5V / 1.0A charging Support mobile app to send emoticon commands Support more than 17 dynamic expressions Support RGB 7 color (red, green, blue, yellow, green, purple, white) display Led resolution up to 512 lattice Support low voltage prompt detection Built in 4.2v/1700mah rechargeable battery, low power mode standby for more than half a year, 70 times a day, can work for a month. The connection distance between mobile phone and equipment is more than 6 meters.