This Detech 18" x 15" SEF Butterfly Search Coil is for use with the Whites Spectra V3, V3i, MX5 metal detectors. By upgrading to this coil you will achieve the best depth and most accurate pinpointing. Compared to traditional DD coils, the patented SEF coil technology provides you with more stable operation, better ground balancing and the most accurate target identification. Search coil cover is included.