The PS 35 Ferrodetector look beneath the surface to locate hazards within concrete and masonry that may present a safety risk when performing coring and drilling work. The detectors can locate reinforcing bars in concrete up to 43/4 in., as well as copper or aluminum pipes in concrete or masonry up to 3 in., with an accuracy of ± 3/8 in. They offer single-button operation and red and green LED indicator lights.