Y.D.F 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.: Amazon.co.uk: Electronics
KOKKIA 4-pole (Left Audio, Right Audio, GND, MIC/Remote Control) 5 Way 6 Port Audio-Splitter (3.5mm) , for Speakers and Headphones: Amazon.co.uk: Electronics & Photo
Mini 4-way Stereo Audio Switch Box Speaker 3.5mm AUX Headphone Selector Splitter | eBay
Tomost 4 Way Port 3.5mm Headphone Splitter Cable 3.5 TRS Stereo Jack Earphone Audio Stereo Lead cord for Mobile Phone Tablet Speaker Mic Headset Smartphone: Amazon.co.uk: Electronics & Photo