I don’t really know much about M.2 slots and the different capabilities and how the key type corresponds, so I don’t want to spend money on something that won’t work.
There’s an unused slot on the motherboard marked ‘M.2 PCIe / SATA1’. I believe it’s M-keyed.

Can it be used with an M+B keyed adapter like this one? Or will it physically fit, but the socket itself isn’t wired to work with an ethernet adapter? Is there a command I can run to figure out the capabilities of that slot?
My plan is to use this machine as an OpenWrt router to replace the shitty Linksys one my ISP supplied, but it would obviously need a second ethernet socket. My home wifi is dealt with by a TP-Link mesh network, so I don’t need it to have wifi and bluetooth. I could use the slot that the networking card is using, but if I can retain those then that would be ideal for any future flexibility I may need.


I had never seen or heard of anything like this before, but apparently it is possible to do, at least Amazon sells something that matches the description you’re looking for:
If you have access in your region, I’d say go for it and if it doesn’t work, return it if your region has a good Amazon return policy like mine does. Can’t hurt to give it a try if the description matches what you have.
I buy off AliExpress sometimes but I don’t know much about their return policy, hence why I suggested Amazon instead to try it out and return if it doesn’t work.