quick searchSennheiser HD 400S Over Ear Wired Headphones - Black (unused £40)Sennheiser HD 400S Over the Ear Headphones - Black (used £25)Sennheiser HD 400S Over the Ear Headphones - Black...
got mine from eBay £20 originally £70. they were an Amazon return. it said on the box "r side not working" obviously some people can't read instructions - you have to turn the 2.5mm plug once...