3pcs Double Jack 6.35 Connector 6.35mm Speaker Mono Plug to 2x6.35mm mono JACK Connector/audio adapter - AliExpress

3.5mm Female 1/8 TRS Stereo to Dual 2x6.35mm Male TS Mono Y Splitter Cable - AliExpress

3.5mm 1/8 TRS to 2 x 6.35mm 1/4 TS Mono Y Cable Splitter Cable For iPhone, iPod,Laptop,CD Players,Power Amplifier,Mixer - AliExpress

JOINAUDIO Solder Free 1/4 Mono TS Guitar Pedal board connector (4pcs/set) - AliExpress

3pcs Double Jack 6.35 Connector 6.35mm Speaker Mono Plug to 2x6.35mm mono JACK Connector/audio adapter - AliExpress

Audio Cables & Adapters, Television Accessories, Home Entertainment - PicClick AU

5Pcs 6.35mm Dual Mono Stereo Audio Jack Plug Converter r 1/4Inch Male to 2x6 .35mm Female Headphone Socket Microphone Connector - AliExpress

Audio Cables and Converters Archives - Skyray Electronics And Gadgets Store

2 pcs/lot Mini Stereo 3.5mm Audio Jack Male to Dual 3.5mm Female Double Earphone Headphone Y Splitter Adapter Plug for MP3 Phone - Price history & Review

2 pcs/lot Mini Stereo 3.5mm Audio Jack Male to Dual 3.5mm Female Double Earphone Headphone Y Splitter Adapter Plug for MP3 Phone - Price history & Review