The Fisher F4 metal detector initially comes equipped with an 11-inch coil that is well suited for universal search. The Fisher F2, on the contrary, has a meager coil with little detection depth. See the photo: an alternative Mars Tiger coil for Fisher F2 and F4 metal detectors.
Mars Tiger coil. It’s made by an alternative search coil manufacturer and produced for different metal detectors. Type: DD. Shape: ellipse. Size: 12.5 x 9.5 inches (32 x 24cm).