Unidens QT206 Digital Depth Finder is as reliable as it is accurate. QT206 has a frequency of 200kHz and 250 Watts of power, the Unidens QT206 reads depth from 2.5 to 200 feet. In water shallower than 15 feet it displays depth in 1/10 of a foot increments when the depth of water under your keel is critical.