Amazon.com: NANYI 1/4 Inch Female to 1/8 Inch Male Stereo Headphone Adapter, Upgrade 6.35mm Jack Stereo Socket Female to 3.5mm Jack Stereo Plug Male for Headphone, Amp Adapte, Black 1-Pack : Electronics
Pressure Gauge Adapter, M16 Male & Female, 1/8 NPT F Tee - Pegasus Auto Racing Supplies
Amazon.com: VCE 1/4" to 1/8" Adapter, 3.5mm 1/8 inch Male to 6.35mm 1/4 inch Female Audio Jack Gold Plated Adapter for Amplifiers, Guitar, Home Theater Devices, Laptop, Headphones - 8 inch : Electronics