Feature: 1) Functions: a) Used chiefly for hydrolocation in seas, rivers and lakes b) Using special technology, can work using either one or two resonance frequencies c) Using wide-band technology, receiving sensitivity and transmitting response are very high d) Fine resolution of fore-and-aft clearance reduces blind zones e) Providing temperature transducer 2) Material: seawater resistant brass shell and stainless steel bolt 3) Specifications: a) Cable (m): 15 b) Weight (g): 880 c) Double frequency (kHz): 43 / 200