http://www.evga.com/articles/00952/EVGA-Z170-Motherboards/
Scroll down about half the page to see the Stinger. Under internal I/O it lists M.2 Key E. The other photos show what is included, other than the board, inside the box and you can see the adapter, and the physical keying of the M.2 slot.
And yes, this looks like 2242.
---
I'm looking to reduce the number of power cables in my current build, and get away from the 2.5/3.5 storage solutions, and AHCI. Some cables are required, of course, and my still desiring ODDs will add some more, but throwing an NVMe drive on a 4 lane M.2 would be good for me. (Hence why I said the Stinger doesn't work for me)