Pipehorn's introduction of Subsurface Water Leak Detectors. The LD-7 is an easy to use, high value option that solves many of the simpler solutions. The LD-12 adds multiple filters and a meter to help pinpoint your leak. In places where background noises are heavy, the LD-18 includes an intermittent noise filter for extra clarity. For more information call us at 205-956-3710 or visit us at www.pipehorn.com.