Adapter 6.3 mm jack to 3.5 mm jack | In-Ear, Noise-Canceling, Wireless, Bluetooth, Music; Entertainment, Travel, Sports - Sennheiser Discover True Sound
Sennheiser Cable Adapter Female 1/4" 6.3mm to Male 1/8" 3.5mm Plug - Audio Equip
Sennheiser HD 660/650/600/6XX/580 1/4 6.3mm plug replacement Cable
Sennheiser 3.5mm Mini Adapter Cable 506052 B&H Photo Video
Sennheiser Cable Adapter Female 1/4" 6.3mm to Male 1/8" 3.5mm Plug - Newegg.com