Sometimes a servo will buzz or chatter continuously. Some poeple find this very annoying. The No-Buzz goes in line with the servo cord and quiets the servo. Here is how it works – if the servo is stopped in the same position for more than about a second the circuit turns off the servo. If the servo starts moving again it will turn it on and drive the servo until it stops again. When the servo is stopped the gears will hold most switches in place. If you use the SwitchWright geometry then the wire acts as a over-the-center spring and also holds the points while the servo is off. A side benefit of the No-Buzz is that you do not need to adjust the servo as precisely but can overdrive the position and let the servo relax back after it turns off.