Amazon.com: Geekria Audio Cable Compatible with Sennheiser Momentum 4 Wireless Momentum 3 Momentum 2 HD 400S HD1 HD 4.50 SE HD 450BT HD 4.40 HD 4.30G Cable, 2.5mm Aux Replacement Stereo Cord (4 ft / 1.2m) : Electronics
Sennheiser HD 4.40 BT Wireless Review - RTINGS.com
NeweggBusiness - Sennheiser HD4.40 BT Bluetooth Wireless Headphones
Sennheiser HD4.40 BT Bluetooth Wireless Headphones - NeweggBusiness
Sennheiser HD 4.40 BT Over-Ear Headphones - Black for sale online | eBay
Sennheiser HD 4.50R - Headphones with mic - full size - Bluetooth - wireless - NFC - active noise canceling - black, red - Walmart.com