HifiMan Electronics Edition S Open/Closed Back On-Ear Dynamic Headphones (Black) Enter Edition S, an on-ear model worthy of the HIFMAN name. In the company's long-established tradition of creating remarkable performance, Edition S establishes a new benchmark for the others to follow. High Performance - With a sensitivity rating of 113dB and impedance of 18 ohms, Edition S can be driven by most portable audio devices and sound simply great doing it! Open/Closed back design - HIFIMAN gives you the best of both worlds with an on-ear headphone that can go from one more to the other simply by adding or removing the logo cap on the ear cup. Portable and Foldable - Only 8.74 ounces, Edition S can be easily folded and stored in its supplied travel case. Ideal for music lovers on the go. Asymmetrical ear cups are designed to contour to the shape of the human ear for comfortable listening for extended periods. Connectivity technology: wired