I have very recently purchased a RenaultZoe ZE50 which came with a Chargemaster unit. I received an untethered unit which works really well. It has a locking key which restricts access to the charger. I do not use that as I doubt whether anyone is going to park on my drive for a few hours to steal my electricity, but I can see how this would be very useful in some locations. I do wonder whether I should have had a tethered unit installed as it would be less hassle, as I would not have to keep getting the cable out of the boot. Overall I am really pleased with the charging unit.