OPTA BH001 On-Ear 3 in 1 Bluetooth Stereo Headsets - with Microphone + HD Deep Bass + Stereo Hi Fi + Bluetooth 4.2+ Wireless/Wired - Silver Colour:Silver   OPTA BRINGS THE BEST STEREO WIRELESS HEADPHONES   Hi-fi sound stereo headphones Wireless plus Plug n play* rechargeable battery and built-in bass port by leveraging OPTA technology.   The OPTA wireless headphones is the ultimate portable audio solution for indoor or outdoor playback - a proprietary driver and a tuned bass system is loud and crystal clear sound. OPTA audio performance from a headphone that is Lightweight comfort headband which is 2D- Axis folding mechanism easy to transport that fits backpacks onto clothing. At OPTA, we develop performance some consumers didn’t even know was possible from a headphone.   OUR Wireless plus Plug n play headphone AT A GLANCE   :::Rechargeable battery:: Frequency response:::18Hz - 24Hz:::Rated impedance: 32 ohms::: S/N ratio?108dB   Jack plugs available: 3.5mm to 6.3mm