A bulk material storage bin has an upright wall supporting a plurality of vertically spaced indicators providing a person with visual information regarding the level of the bulk material in the bin. The indicators have bright color and dark color surfaces that are selectively displayed to provide a person with information of the level of bulk material in the bin. An actuator located in the bin cooperates with a motion transmission apparatus to move visual members to an ON position displaying the bright color when the bulk material engages the actuator and to an OFF position displaying the dark color when the actuator is free of bulk material. The motion transmission apparatus includes a rod movably retained on an O-ring held on a mount device secured to the side wall of the bin. A yoke supporting an endless flexible member mounted on the rod is connected to the visual members whereby movement of the rod moves the visual members between the ON and OFF positions.