This mod enables you to adjust the volume on most Stern SAM, SPIKE, & SPIKE 2 system pinball machines without opening the coin door. The unobtrusive switch is mounted in the extra opening just below the start button (if a tournament button is installed in this opening it will have to be removed). This button can be used anytime when the game is on or being played. Installation is simple and no permanent modifications to your game are required. Complete instructions are included.