A word to the wise (and those considering EVSE Upgrade ), if you order an upgrade to a unit that is specified to have the L6-20 Plug, and you order any adapters with the L6-20 ends, you may get a phone call when they receive your unit, asking about which plug end you want. I opted to keep the L6-20 end on the unit (under the assumption that the adapters would still have the L6-20 ends. Turns out, they are planning to phase out the 20 amp ends and only use the L6-30 ends, so I received my adapters with L6-30 ends with the unit having an L6-20 end. This is not the end of the world, since I purchased the L6-20 to L6-30 "Dogbone" adapter. However, I don't like the idea of relying on the dogbone to use either adapter, not to mention the extra connections that need to be made.
I called them after receiving my order, and they are offering to switch out the adapters for L6-20 ends once they receive a shipment.
On the plus side, the unit works well, juicing up from 2 bars to full in 12-14 hours at 10 amps, level 1.