Good construction quality. Original device especially if you want to make a prototype gift. By pressing "start", it completes the cleaning in one minute. As for whether it sterilizes well or not, I'll be honest: I HAVE NO IDEA. We cannot know how dirty a device is and therefore how well it sterilizes. I think we all have the same concern because none of us have tangible evidence of the imposed bacteria that our phone or keys had before sterilization and how many bacteria it has afterwards. Let's hope it does its job.