Is there a way to identify US and UK versions unopened?

[botchok5]

Hey there,

I was wondering if there is any way to check out if it's a UK or US model based on the boxes?
Because I'm after a MacBook Air 13", but I can get it cheaper from a few established seller from eBay for £200 cheaper than the Apple Store. However, a few of them I noticed are US version, with the annoying horizontal "enter/return" key.

 

[will0407]

size of the box is different.The US box isn't as wide as the UK model as the extension plug goes under the laptop in the US one, but goes at the side in a rectangular box in the UK one.