Correct DC power plug size for a M64

What is correct DC power plug size for the M64? I know I can power it with the micro-B (OTG) connector, just like my Raspberry Pis, but I would like to use the OTG for something else and want to use the DC barrel jack. I believe it wants 5V at 2Amps.

4.0 x 1.7mm

Good luck. You will need it.