Amazon.com: Sennheiser HD 4.50 BTNC Bluetooth Wireless Headphones with Active Noise Cancellation, Black and Silver (Discontinued by Manufacturer) : Electronics
Amazon.com: Geekria Sport Cooling Gel Replacement Ear Pads for Sennheiser HD4.50BT HD4.50 HD4.50BTNC HD4.50SE HD4.40BT HD4.30G HD4.20S HD458BT HD450 HD450BT HD400S HD350BT Headphones Ear Cushions (Black) : Electronics