Highly visible 4 mm multicolor LED (colours: red, orange, green, blue, purple and white). LED colour is easily changed using the rubber push button on the back of the bite indicator. Two-stage sensitivity adjustment. Stepped adjustment wheel for volume. High quality conical speaker. Integrated I-Com radio transmission technology for use with the MX radio receiver. Rubber inserts in the bite indicator tubes. Tru-Run wheels. Toggle switch with three positions for on/off and sensitivity adjustment. D-Tech sensor system. Silent switch-on. 1 x power socket for illuminated optical bite indicators. Hardcase included. Requires 2 x AAA batteries (please order separately).