A ter'angreal in the city of Far Madding. It consists of three cloudy crystal discs a span wide. Each disc has a narrow clear crystal wedge and gradations around its circumference. The guardian creates three zones around the city. The innermost zone ending at the bridges to the city cuts off women from the True Source. A larger zone that cuts off men from the True Source extends about a mile outside the city. A still larger zone detects a man or woman channeling outside the other zones. When use of the One Power is detected, the three wedges point toward the source allowing the channeler's location to be determined by triangulation. The wedges turn red for saidar and black for saidin.

References (Possible Spoilers)#