I received this product on time, but I quickly realized that it does not operate. I warned the salesman who told me they have never had any problems with this material and proposed me to return it, but I did not have the packaging ... Considering the price back, I think I'll buy me another pharmacy. The Roaring data of this device does not reassure us they provide measures that my husband has ever had. It was for a regular monitoring of its tension, and well it missed, it is in a drawer and not a question of using it !!!