Talk about a pair of underrated headphones that continue to stand the test of time. These over-ears promoted one of the most comforting listening experiences thanks to a lightweight design accompanied by Koss’ signature “comfort zone” setting and three mechanical settings to adjust the tension of the earpiece against your dome. It's inconceivable to think such a great sounding pair of headphones came priced lower than a $100. In fact, the PortaPro’s became such a popular option throughout the past two decades, Koss re-released it as part of a special 25th anniversary edition bundle in 2009. How’s that for longevitiy.