Belkin Rockstar unpowered splitter (five 3.5mm outputs) for $5.80

If you are looking for a basic and portable unpowered headphone splitter, the white-green color scheme is currently on sale for $5.80 per set, with a limit of five per shopping cart at Amazon.com. The other colors go for more. It has one 3.5mm input and five 3.5mm outputs. This is not powered.