For anyone attempting to do this as a means of troubleshooting, be aware that as soon as you disconnect the SSD, the device will not power on. Highly unhelpful when you suspect a failed drive and you need to do a quick test without. Nicely made devices, but not reliable in the slightest. Very bad when you consider the price of them.
I must admit I've not heard that term before, but having just disassembled one it had a regular NVMe SSD, but it was the smallest length available 2230 I believe.