Specification AKG K845

Driver size
20 Hz - 20 kHz 
Design Closed-back
Color Black or White
Frequency range 20-20kHz
Impedance 32
Max input power 50mW
Sensitivity 102dB @1kHz/1mW
Bluetooth transmitter frequency range 2.402~2.480 GHz
Bluetooth transmitter power 0~4 dBm
Bluetooth transmitter modulation GFSK, π/4 DQPSK, 8DPSK
Battery Lithium polymer(3.7V 320mAH)
Listening time on battery power 8 hours
Battery charge time 3 hours