I used this on an outside outlet to connect to the AeroVironment TurboCord 240 volt plug in EV Charger. This was an easy install and does a great job of hiding the blinking blue TurboCord LED. I have a Masterlock 22d padlock on it that fits. The outlet was a 20 amp, 250 volt, slim Leviton 5822-I duplex outlet, so I didn't even have to change the stock plate in Intermatic. Installation took about 10 minutes.