ER2243B Highlights Compatible with smartphones and MP3/MP4 players Perfect audio transmission function Provides hands-free conversations through your car speakers Full frequency range design effectively avoids interference Easily charges your mobile phone and other devices  General Specs Transmitting Distance About 5 m Frequency Response 20Hz-16KHz Separation 40 dB S/N Ratio ≥ 45 dB Plug & Interface 3.5 mm plug， 8-pin port， USB Package Details Weight: 74.90 g Size: 17.5*9*3 cm