The RENS A20 search coil metal detector is manufactured to be extremely durable and precise. RENS detectors have become an industry leader and have been producing high-quality metal detectors for over 70 years. Precisely, the A20 search coil can detect a 1" steel ball up to 19" from the coil face, this includes ferrous and non-ferrous metals. This range allows a wide range of versatile applications and fittings for this detectors. We also supply the control unit and custom fiberglass troughs for the metal detectors. For more information or to get a quote, please contact us and we'll be happy to assist you.