This unit is small and light. It holds a solid amount of medication and is easy to use. I bought a pouch so I can carry in my purse. I got the AA battery only and I get VERY LONG battery life. There isn't always a plug available but 2 AA batteries is a snap. It also has a warning light when the batteries are low. That was a concern but I was super surprised that the batter life was so strong - like 3 months strong. I also liked that the medication doesn't slosh out but it will if you lay the unit on it's side or hold upside down. It would be a perfect piece of equipment if the medication chamber was totally sealed since I rarely use a whole vial at a time. Oh, price was best I've found too. I'm thinking about getting a spare but rather than that I've got spare parts for anything that might break.
The mask was bent when it arrived and is still usable but will always be bent.