I made an error by giving a bad review about Smoant China vape units and supplies customer service and want to correct it. I said they don't reply to emails, but they do if you send from your email account. Do not use their online email on their website; I did not get a response. But when sent from my email account, they replied promptly. They honored thire 90 day warranty on a failed unit I bought that the buttons fell off and it quit working. It was a quality unit and worked well until the buttons fell off. They sent me one of their new models as a replacement at no cost; and shipped it expedited from Hong Kong as well, so it was received in only four days! Very pleased with Smoant in China and can highly recommend!