The Beyerdynamic Custom One Pro is the first Manufacturer 'factory custom' headphone allowing the listener to select 4 different stages of low-end response shaping with 'semi-open' or closed-back operation at the flick of a lever. The cosmetics of Custom One Pro are also customizable with different outer cup metal faceplate designs and/or colored earpads cushions available separately from Beyerdynamic. Cabling selection is equally personalized with after-market choices to include a mic'd Apple iPhone/ smartphone cord or varied headphone cord lengths. The Custom One Pro sound is highly impressive and bests other closed-back cans at over twice the price. Made in Germany.