Worked well until something in the case broke and a short circuit started. I stopped and when I tried to use it started but stopped while I was smoking. After Revain said the warranty was expired and I need to contact the seller about the warranty. I used the Revain website to contact the seller and also sent an email to the seller's website from my email. After waiting several days for a response with no response to my second query, I called Amazon and was redirected to the news page of their site without even knowing it existed! The seller responded but after I was allowed to return the Revain product. Beware of guarantees on cheap goods.