the off button disconnects regularly. One click to open a web page (normal) one click to make it disappear (normal) without being able to navigate it (not normal) that is to say that if you click on a tab not there napparaƮt IT GOES with any button after a while it becomes normal so I do not know !!. A button for a variation dpi which obviously makes no difference. Poor quality plastic not really nice as well as ergonomics. Clicking there are sharp edges in short, a big disappointment. This mouse to function poorly. After two days I return to the store. I add that the nano USB connection is to sink strength, same for the exit. Far too expensive for this poor !!