The LD-18 digital water leak detector from SubSurface Leak Detection offers automatic noise reduction from intermittent interfering noises, like passing vehicles, people talking and pedestrian footsteps. It can be used to find leaks quickly and easily, as it uses an amplifier to easily identify leak sounds. The all-digital amplifier has automatic noise reduction of environmental sounds, high and low filters, and storage and graphing of leak noises at different locations on the pipe. It uses a bar graph and numeric display of sound volume, and it has a USB connection and backlight. It includes five high-frequency filters, three low-frequency filters (plus low filter off), and two notch filters (plus notch filter off) to remove continuous interfering noises. 408/249-4673; www.subsurfaceleak.com.