The triple-antenna Tracker 2 switches from transmit to search mode when you pull the large tab at the base of the unit. In search mode, five LEDs indicate direction and a digital screen shows the distance, in meters, to a buried victim. In a multiple-burial scenario, the Tracker 2 isolates the strongest signal within 10 meters, but the lack of a mark function means you can’t block the transmission signal of a located victim. [$335; backcountryaccess.com]