Update (05AUG20): The power adapter is still working fine for powering my Ring Pro after 2 years. Hope it keeps on working.
I got a Nest Hello and wanted to move my Ring Pro to my back door since my Chime Pro’s stopped working for some reason and so I got the Sikoimate Power Adapter, Video Doorbell Power Supply for the Ring Video Doorbell, Ring Video Doorbell 2 & Ring Video Doorbell Pro, Power Supply, Adapter, Battery Charger from Amazon for $17.79.
After I had hooked it up to a waterproof outlet outside and hooked it up to my Ring Pro and so far even through the hot heat recently it has worked fine in powering the Ring Pro, no issues with voltage or anything like that. The motion detection while on this power brick work the same as it did when it was plugged in at the front door on the transformer.
I’ll post more about it after I use it some more but so far it works fine as intended. Let me know if you have any questions, I will try to answer them the best that I can.