Mp3 earphone for helmet
1.Double SPK fixed inside of the helmet, have no pressure to ears.
2.Coil PU cable retractable use .
3. Can be use for MP3, IPOD, CD ect.
SPK：
Size：36mm
Audio pressure level：90dB+/-3dB
Impedance:32 Ω+/-15%

Audio output:200mW