KabelDirekt – 3.5mm Y adapter & jack & AUX splitter (1×3.5mm male to 2×3.5mm female, connect two sets of headphones to a smartphone/tablet/notebook, stereo, 4in, black) - Walmart.com
Mini 3.5mm Plug Jack to 2 RCA Male Music Stereo Audio Y adapter Adaptor Cable Kabel Cord AUX for Mp3 Pod Phone TV Sound Speakers - Newegg.com
Amazon.com: UGREEN Headphone Splitter 3.5mm Audio Stereo Y Splitter Cable with 3.5mm Audio Cable Male to Male 90 Degree Right Angle 1.5FT : Electronics