Q: How many charges of my iPad Pro can I get out of the Plugornot Zero (wall charger/power bank combo)? How long does it take to charge an iPhone X fully?
A: Your iPad 2016 model has a fairly large battery with a nominal capacity of 27.9 watt-hours. In comparison, the Plugornot Zero is rated for 24.3 watt-hours. The conversion efficiency is about 70% (some stored energy is lost in the conversion process inside the Plugornot Zero, and some more is lost inside your iPad.).
A fully charged Plugornot Zero can charge your iPad from 0 to 60%-70% full. The Plugornot Zero will then run out of battery, and you will need to recharge it by plugging it into the wall. (You can charge your iPad with the Plugornot Zero while it is being recharged.)
The iPhone X has a much smaller built-in battery with a nominal capacity of 10.35 watt-hours. Using the same methodology, the iPhone X will get about 1.6 full charges on a single full charge of the Plugornot Zero.
The Plugornot Zero will also charge your iPhone X about twice as fast as your stock iPhone square plug. The Plugornot Zero will charge as fast as your iPad's stock power brick if you only charge one device at a time. If you use both USB ports on the Plugornot Zero, the charging speed will be reduced.