There's not much you can do to improve on a pair of headphones, but Comply foam is designed to replace the crappy rubber nubs that come packed with your in-ear phones. They're made from highly-durable foam that softens with the heat from your ear canal. Squeeze them in and they expand, totally filling your earhole and creating a much better seal. Because less sound escapes and ambient noise gets in, you can listen to your tunes on a lower volume and reduce the chances that you'll be walking around with a listening horn stuck in your ear by the time you're 32. They're made to fit most decent headphones and the Tx models have a sonically transparent earwax guard to keep all that head crap from filling up the delicate caverns of your pricy headphones.