Philips A1 PRO/27 DJ headphones for $55

It looks like a trio of marketplace sellers have price-matched each other as the new condition Philips A1 PRO/27 headphone, under the Armin Van Buuren umbrella, is on sale for $55~ with free shipping, with the orders fulfilled by Amazon. These are closed-back with 40mm drivers and 16 ohm impedance. They rotate and fold and have detachable earcups. From the looks of in the picture, the detachable cable may be proprietary design?