The switch has some issues, contact issue. It is a design flaw. It does not stay on. If I turn it on, it does not always turn on. In short, it is not reliable! Also on charging. I have no way of knowing when it is fully charged because the amber light stays on all the time! Also the on and off switch should be color coded. Sometimes I have to look very close to see what position the switch is on. When one is very busy one has no time to deal with this problem. I just put this one away and use my old scope. Once I got it to work it seems fine but does stay fine for long.