This bluetooth earphone can also connect to digital device via 3.5mm jack cable; supports FM radio when the TF card slot is not in use; can control music play phone call volume on the earphone; compatible with all mono track bluetooth earphone; FM range: 87.5MHz~108MHz; bluetooth device mode: HSP HFP A2DP AVRCP; frequency range: 2.4026GHz~2.4835GHz; frequency response: 20Hz~20KHz; SNR: 70dB; transmission power: Class2; USB 2.0; TF: 1~32GB; audio format: MP3; audio sampling rate: 8~48KHz (MP3: 8~448kbs WMA: 32~384kbs); radio time: 8 hours; output power: 2 x 15mW; speaker: 40mm; resistance: 32 ohm; audio jack: 3.5mm universal