(Im not an engineer btw) I purchased a new one so I cant speak about the bad reviews on the used units (you get what you pay for). I havent had to recharge it very often, either. dr martens quad black Update : still going strong 6 months later. Not quite as comfortable as a previous pair, I suspect its because these have leather straps instead of the softer "Birko-Flor nubuck" of the other pair I have. dr martens quad black I am happy to say these fit my ears well, although your mileage may vary, I am also pleased to say that they have surprisingly good bass response for this type of headphone. dr martens quad black Charger stopped working after a single time use. The sole is thin reminds me of those a nail salon gives us when we forget to bring our own sandals and got a pedi. Just a heads up if one is wondering. dr martens quad black The bottom is a cheap hard plastic rather than a grippy rubber. Suelo comprar la marca e incluso me queda ancha siempre, y este venia sumamente apretadas mas correas, voy a devolver
dr martens quad black