Well, might as well say right away that I bought this piece of plastic for very little. What makes his intrt is just the price and we pay for: achte on the cheap, you pay crap. The contraption has held a week before lcher. I'm all like crazy (well no, it's a tuning pedals) is when I changed the battery contact plate + / - I rest e in the fingers. Rsultat: I have to buy a transformer. Otherwise it is not super prcis, cheap, not ergonomic, boring death to change the battery (it is better to have two pens on oneself and patience, I'll say no more, try) .. . short, much more money to have something reliable.