Color: T10- khaki (touch), T10- black (touch), T10- white (touch), C021- black (touch digital display), A16C- black (digital display touch), W1 black (keystroke), C021 white (touch digital display), Air 2S- black (digital display touch), white (digital display touch) Bluetooth Protocol :5.0 Transmission range :10 m Channel: Stereo Can LOGO: Be printed Single binaural: Bilateral stereo Functions: Power display, call function, support music, multi-point connection Usage: Earplug