TCL Neckband (in-ear) Bluetooth + ANC Headset, HRA, Frequency: 8-40K, Sensitivity: 100 dB, Driver Size: 12.2mm, Impedence: 32 Ohm, Acoustic system: closed, Max power input: 30mW, Bluetooth (BT 4.2) & 3.5mm jack,HiRes Audio & ANC, Color Midnight Blue