S.E.F. (Symmetrical Electromegnetic Field) coils, also known as Butterfly coils. These searchcoils combine the advantages of both DD and Concentric coils:
The S.E.F. Butterfly search coils offer better ground balance, more stable operation in all conditions, even deeper in the ground and more accurate target identification.
Detech coils are made using high quality materials. The housings are made of UV protected material. Their inner side is covered with chopped-strand material for a better shock resistance. We use resins, which are transparent for the electromagnetic waves, and perfect shielding. The coils are water resistant, and operate in a wide temperature range. The searchcoils are standardly equipped with excellently fitting cover, and have one years full warranty.