A Toggle Latch changes the output state every time one of the two input sides turns on. It has two output sides, one normally on, one normally off. This changes when an "on" input comes into the input side. In redstone mechanics, this is refered to as a T-flip flop. This is different than a RS NOR latch because it will only change state with an input turning on. A RS NOR latch will change even when one of the inputs turns off. The toggle latch is one of the most commonly used logic devices because it sends out a constant signal and is easy to understand and change. One of the features of the toggle latch is that its state can be changed manually.