gday mate i dont know how mny there is but the 1 i got seems ok ill take some pics that will explain its self seems to work on a circtut board covered in some kind of plastic membrane very easy to use with left right & speed control i have heard that there is probs with them from other meembers so far i havent had any but mine is 6months old so time will tell wacko sugested to go for maxim i think it is so id look at them as well if ur getting a electirc if ur just after pedals ima not sure