Monoprice Enhanced Bass Hi-Fi Earbuds Headphones with Built-in Microphone and in-line Controls Compatible with Android Devices - (111616) These earphones feature 6.5mm magnets and an impedance of 16 ohms. They boast a 20Hz ~ 20kHz frequency response at 3mW, a 108dB sensitivity, and less than 5% THD at 1kHz. which places the ground on the second ring of the TRRS plug instead of the sleeve. Note that when used with Apple iOS devices, only the volume controls will function on the in-line controller. If you have an iOS device, you should order the Enhanced Bass Hi-Fi Earphones with Built-in Microphone and In-line Controls for iPhone, iPod, and iPad V1.2 (PID 9980) instead.