SE GP-MD15 Fine Tuning Metal Detector with 6-1/2" Diameter Waterproof Search Coil and Adjustable Stem Metal detector is great for treasure hunting in many different terrains, including shallow water Waterproof search coil is 6-1/2" in diameter and can be used in uneven terrain, tight spaces, and shallow water Change in tone increases when non-ferrous metals are detected and drops off for ferrous metals Large easy-to-read controls for sensitivity, volume, battery test, and discrimination tuning Dimensions: total length is 26" to 37" with an adjustable stem that extends from 15" to 27"