AKG has just announced two new pairs of on-ear headphones that are available now. First up is the K 490 NC, which is rated for 40 hours of active noise-cancellation. When the power runs out, the music will keep playing (albeit with only passive noise-cancellation). The headphones are charged over USB, and audio goes over your typical 3.5mm headphone jack. The pair will set you back by $249.95. The company has also announced the $349.95 K 495 NC headphones (pictured above), which are the same in nearly every way, though they do come with an extra-long 3.5mm headphone cable that you can swap for the standard-length cable. Otherwise we're not sure what that extra $100 is going towards, though AKG promises that it offers better sound quality. You'll just need to take AKG's word for it until we get to spend some time with both pairs at CES next week.