Urbanears Medis In-Ear Headphone, Moss (4090852) Ear click For A Stay-In-Place Experience The Ear Click solution ingeniously secures the earpiece in two places rather than one, relieving pressure while keeping it firmly in place. Microphone & Remote For Hands-Free Talking Most music devices today are also cell phones. That's why all our headphones come with a built-in microphone and remote. Use it to pick up calls, or fast forward or rewind your music. Audio 15.4mm Handmade Drivers Frequency Response 20Hz-20kHz Impedance 32Ohm Sensitivity 115dB Max Input Power 5mW