its small and cheap and idiosyncratic but do not dismiss this tuner without giving it a try. You pluck the string and it signifies the wrong note - that is because it is either wound too tight or not tight enough. To get to B you sometimes have to pass through G by winding on the string. It makes sense if you think about it. ONce you get into the tuning range the red lights come on , generally the one pointing left - keep plucking and winding SLOWLY until you pluck a green light - then you are home and dry and in tune. It might surprise you how quickly new guitars lose tune but this gadget will keep you in tune without busting a string.