Got a used HP Probook laptop. Just needs a new drive. HP specs say it has an m.2 2280 slot. So that’s what I ordered. Guess I needed to look closer.
edit: Thanks for all the info, guys. Different types of keys are explained here. Gonna have to look for a sketchy no-name brand.
One of the universal truths is that a drunk sailor with a fistful of money could simply not buy anything on the HP site before he sobered up. That site is the hallmark of super-bad site design, and always has been.