Shure's dual-driver E5c headphones have long been one of the best (and most expensive) sets of off-the-shelf in-ear headphones you can buy. This week at CES, the company is pushing the high-end even higher, with their new US$499 E500 model, their first triple-driver headphones designed for the mass market. Shure has packed two woofers and a tweeter into each earpiece of the E500, with the drivers setup in a two-way configuration.

Any design that improves on the E5c is bound to sound pretty good, but it's the other tweaks Shure has made that really caught my eye. The E500s ship with a Push to Hear module that lets you flick a switch to pipe external sound into the headphones through an included microphone--a nice feature to have if you need to briefly leave your sound-isolated state and reconnect with the world. The PTH module plugs into the E500's new modular cable system that comes with one- and three-foot extensions so you can get exactly the cable length you want on your earphones.

Shure plans to ship the E500s this May.