This pair of Guardian headphones from Hamilton Electronics help outsiders identify whether listeners are adhering to save volume levels or not, courtesy of the green and red LED lights located outside. Whenever the LED lights up in red, that means volume levels are cranked way higher than they should be. It is best to instill this habit in kids to protect their hearing, but surely a little outside help won’t hurt. Each pair of Guardian headphones retail for $39.95.

Source: I4U