1/4" Stereo Audio Jack Plug Adapter Single Male To Female 6.35mm Dual Mono Stereo Jack Headphone Microphone Y Splitter Converter - Audio & Video Cables - AliExpress
Hosa Mono 1/4" to Stereo Mini Adapter Cable (5 feet) Adapts a 1/4" TS jack to 3.5mm stereo minijack at Crutchfield
3.5/6.5mm male to female Plug Jack Adapter Stereo/Mono Connector Audio Headphone | eBay