It used to be included with the car, but if you don't have one, it is probably one of the first adapters to get.
The J-1772 chargers are not fast chargers, adding varying amounts, but average around 30 mph charge rate.
The big advantage is that they are all over the place and sometimes available at business and hotels, as they are considered a universal charger.
Check plugshare.com for a location of the J-1772 stations.