Amazon.com: Sennheiser Consumer Audio HD 4.40 Around Ear Bluetooth Wireless Headphones - Black : Electronics
Sennheiser HD 600/650/660S Cable 6.3mm/3.5mm/balanced 4-pin XLR and 4.4mm Pentaconn Custom Colours & Connectors Made in the UK - Etsy
Sennheiser Momentum 4 Wireless Headphones - Bluetooth Headset for Crystal-Clear Calls with Adaptive Noise Cancellation, 60h Battery Life and Customizable Sound, Black - Walmart.com
Sennheiser CH800 P Balanced 4.4mm Headphone Cable
Corpse Cable GraveDigger for Sennheiser HD 600 / 6XX / 650 / 660S - 4.