This is the kind of seat-of-the-pants engineering genius that you only find in hackspaces, garden sheds or Shenzhen.
It's not for the faint-of-heart, it's not particularly spec-friendly, but it is useful and cool for Pi Zero hackers!
This tiny little shim pushes inside a full-sized USB connector and transforms it into a USB-On-The-Go compatible microUSB connector.
It's perfect for plugging a single USB peripheral into the Pi Zero with the minimum amount of spaghetti wiring.
Note: Plug into your USB device first, making sure the four contacts are facing in towards the contacts inside the USB connector! It's on you if you put it in the wrong way and things go FZZZZT! :D
Warning: You should also never plug this into a USB-A receptacle 'female' port, only a USB plug 'male' style device. So don't go plugging the big end into your Pi 2's ports :-)