PROTO, 1/4 in_3/8 in_1/2 in Output Drive Size, Square, Socket Adapter Set - 19C375|JHA4S - Grainger
Threading Adapter, NPT 1/4 Female to NPT 3/8 Male
Sennheiser Universal 1/8" to 1/4" Headphone Adapter 549346 B&H
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
1/4 npt x 1/8 npt male union connector
3 Piece Socket Adapter Set Increasing 3/8" 1/2" 3/4" Female 1/4" 3/8" 1/2" Male - Walmart.com
Threading Adapter, G 1/4 Male to NPT 1/8 Female
1/8" 1/4" 3/8" 1/2" NPT Female To Male BSP Brass Pipe Fitting Connector Adapter For Pressure Gauge Air Gas Fuel Water|Pipe Fittings| - AliExpress
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: Thread Reducer Bushing 1/4" Male x 1/8" Female Adapter Pipe Fitting with Stainless Steel 304 NPT : Industrial & Scientific
On-Stage WHA4500 1/8" to 1/4" TRS Adapter | Guitar Center