DEWALT DCT418S1 12-Volt Li-Ion Hand Held Radar Scanner Kit Radar sensing technology detects wood, ferrous metal, non-ferrous metal, PVC and live electric behind walls Scans through surfaces including drywall, plywood, concrete, marble and ceramic tile.Automatic mapping processes all embedded materials eliminating need for calibration Includes the DCT418S1 scanner, a 12-volt MAX lithium-ion battery, a fast charger and carrying case For best results, it is recommended to scan the wall section at several different heights as well as scan both horizontally and vertically. This will help map out the materials and their locations behind the wall surface.Once the materials are identified, that information can be used to deduce the actual object type