Square Reader has always been a handsome and functional piece of hardware, but the designers and engineers at Square have been on a constant quest to make it just that little bit more handsome and little bit more functional. On Monday, Square released a new version of the Square Reader, which has both a sleeker, thinner design and a completely overhauled electronic interior. Square has basically replaced the off-the-shelf components in the card reader with its own custom-designed parts, Square head of hardware Jesse Dorogusker said while giving me a preview of the new device on Skype. In previous generations of the Reader, Square was using the same magnetic read head – the sensor that grabs data from a credit card’s magnetic strip – that you would find in any tape deck built since the 1980s, Dorogusker said. Square felt it could do better, so it redesigned the read head, optimizing it for Square’s tiny form factor.