Ferrous/non-ferrous discriminator distinguishes iron and steel (ferrous) from silver & gold (non-ferrous) * adjustable sensitivity, discrimination and ground-balance controls; Automatic or manual tuning * Ultra-lightweight, ergonomic construction with padded handle, arm, support & extendable metal shaft for comfort * 3 distinctive tones indicate different types of metal; waterproof coil * Low battery indicator; 1/8-inch headphone jack