Massdrop x Beyerdynamic DT 177X GO Over-Ear Closed-Back Headphones, 32 Ohms, Detachable Cable, Replaceable Velour & Sheep Skin Ear Pads. A STUDIO LEGEND, NOW PORTABLE — A collaboration with world-renowned headphone manufacturer Beyerdynamic, our DT 177X GO has the kind of German-made quality you can see, hear, and feel.