21 Inc. Releases First Product, a ‘Bitcoin Computer’, Wall Street Journal, 21 September 2015.
21 Inc. has been very well funded, but pretty opaque about what they are actually doing. They have designed some custom mining hardware, but hard to see how it makes sense as a USB device for individuals. I could see the value in a secure USB device that works as a bitcoin wallet and can be smoothly integrated with a web client, but hard to see the case for including a miner in it.
You can buy it from amazon.com.