Barska Metal Detector Combo &ndash; Accessories Included Adjustable stem from 13" to 19" Adjustable arm rest Auto tune, lets you tune your detector quickly for accuracy Distinctive tones for different types of metals Detects extreme differences in metals, such as iron and gold Tunes out false signals from mineralized soil mode Detects extreme differences in metals, such as iron and gold Detects finer distinctions between metals, such as aluminum and gold Distinctive tones for different types of metals Auto tune, lets you tune your detector quickly for accuracy