Looking a bit like a Big mack, hence the name, this is a communication aid with 20 seconds of memory, which allows a message to be recorded and played back when the switch is pressed. This switch has a clear snap cap under which you can place picture symbols to give additional context to what will happen when the coloured switch top is activated. There's a choice of 4 bright colours for the switch top. Can also be used to activate reward toys using a switching system. Requires a 9v battery. See also Little Mack Switch (S196).