A tact switch can be defined as a small-size, momentary-contact component that converts a human finger push to an electrical signal, while providing the human user a tactile feedback to confirm the operation.  A typical tact switch has a body size of 6 by 6 millimeters and a standing height of 3 millimeters.  Due to its small size, a tact switch is typically rated at 50 milli-amps or less.