Amazon.com: Cable Matters 5-Pack 1/4 to 1/8 Headphone Adapter (3.5mm to 1/4 Adapter, 6.35mm to 3.5mm Adapter) : Everything Else
Amazon.com: SiYear 3.5mm 1/8 inch TRS Plug to 6.35mm 1/4 inch Jack and 3.5mm Female to 6.35 Male Plug Gold Plated Set Audio Stereo Adapter Converter for Headphone, Microphone (4 -Pack) : Electronics
1-1/8" to 1" Headtube Headset Reducer / Adapter 1.125" to 1"
3/8" Male NPT x 1/2" Female NPT Brass Straight Adapter | Fastenal
Insten 1 / 4 Audio to 1 / 8 Audio M / F Adapter (1/4" M to 1/8" 3.5mm F) - Walmart.com
1/8" Female NPT X 1/4" Push Connect Adapter - John Guest - Bulk Reef Supply
Bsp-npt Adapter 1/8" Male Bspt To 1/4" Female Npt Brass Pipe Fitting Euro To Us Pressure Gauge Adapter - Pipe Fittings - AliExpress
Amazon.com: Legines Brass Pipe Fitting, NPT Adapter 1/4" Female to 1/8" Male Reducing Adaptor 1200psi High Pressure (Pack of 2) : Industrial & Scientific
LTWFITTING 1/4 in. FIP x 1/8 in. MIP Brass Pipe Adapter Fitting (5-Pack) HF1024205 - The Home Depot
Everbilt 1/4 in. OD Compression x 1/8 in. MIP Brass Adapter Fitting 800729 - The Home Depot
Everbilt 1/8 in. Barb x 1/4 in. MIP Brass Adapter Fitting 800049 - The Home Depot