There has been extensive discussion of this unit and others over in the Travel Technology forum:
Outfitting your travel kit for USB-C
The Ravpower 45 Watt unit is excellent (I've got one) and is a good example of a new generation of GAN chargers which are all significantly smaller than the old school boat anchors we used to lug around. I've used the Ravpower unit to power my 15 inch Macbook pro, and and my phone... allowing me to travel with a single charger.