... connector: 2.0 / 1pcsAudio Jack: 3.5mm stereo / 1pcs for mic, 1pcs for headphoneCase: high grade plasticSize: 5.3 x 2.4 ... , including R/D, tooling development, plastic injection, color spray & painting, cable soldering, testing, assembly, packing…we take every step in our ... headphone and microphone. - Factory- Certificates- Business Fair- Loading china supplier usb to 3.5mm adapter