There aren’t a whole lot of USB-C chargers out there that can output enough juice to charge a MacBook at full speed, but this iClever BoostCube can handle it, and then some.
Its single USB-C port can push out 45W of power, which is squarely between the 12" MacBook’s 29W and the 13" MacBook Pro’s 61W. That means it’ll charge the former at full speed, and should charge the latter fairly quickly considering it’s only $19 with code N3JQ886V, compared to the $69 Apple charges for a 61W power supply.