Mounting bracket is missing from the package. When I received the replacement the bracket was also missing, to be honest the rating would have been 2 stars because I didn't receive what is shown (2X) but the seller is 1. Responded to messages quickly and quickly replacement sent. 2. They answered truthfully (I think) that their batch was accidentally packaged without a staple. And fix the situation. I haven't been able to use it yet because I have to do braces. But the tests I've been able to run seem to work fine with the actual product, except I was hoping the sleep feature wouldn't be a huge issue, just a thought. ;)