This is the size of the new Android credit card reader by Square. When you insert it into the phone, there is a place at the opposite end to slide the card. Supposedly the company deposits the money right into your checking acc't. It took about two minutes to sign up for the acc't,. Tomorrow I may have the opportunity to use it, so we'll see how it works. I have no idea what happens re: a receipt. Unfortunately, my phone doesn't have a printer (next one probably will) but they say that something about a receipt so maybe it is sent via email??? Isn't this exciting? Makes paying the bill for the android phone a lot easier. (I have a T-Mobil 3G). Imagine not having to purchase one of those expensive wireless credit card machines!