Amazon.com: 4-Jack Multi Headphone Audio Splitter with BASS and Treble, 4-Way 3.5mm (Aux Stereo Audio Splitter, 1 in 4 Out 3.5mm Audio Splitter Compatible for Smartphones, Tablets, MP3 Players etc. : Electronics
Headphone Splitter, 3.5mm Audio Stereo Y Splitter Extension Cable Male to Female Dual Headphone Jack Adapter for Earphone, Headset Compatible with iPhone, Samsung, Tablet, Laptop - Computers Plus
Amazon.com: Qaoquda Stereo Audio Splitter Cable, Coiled 3.5mm Female to 2 Male Spring Headphone Stereo Y Splitter Cable for Home/Car Stereo, Phone, Headset and Speakers (3.5mm 1female/2 Male) : Electronics
1/4" Stereo Audio Jack Plug Adapter Single Male to Female 6.35mm Dual Mono Stereo Jack Headphone Microphone Y Splitter Converter
Zeskit 3.5mm Jack Stereo Audio Splitter – Zeskit Shop
2X 3.5mm Stereo Audio Splitter Cable Gold Plated 3.5mm (1/8 Inch) TRRS Stereo Plug Male to 3 x 1/8 Inch - Walmart.com