PMR Handlebar ButtonThe PMR Thumb Switch is designed so while sitting on the bike the switch is right where your thumb is, with our switch you do not need to take your thumb off of the grip. Some people like to use their horn button for activating accessories like nitrous. Yes this does work and we have used it too but when you are racing the last thing at high speeds you want to do is to have to take your thumb off from around the grip. So we designed this switch to be