SI-TEX SDD-110 Seawater Depth Indicator w/Bronze Thru-Hull TransducerSDD-110 Seawater Depth Indicator wBronze Thru-Hull TransducerThe SDD-110 operates on working frequency of 120kHz, so it wont interfere with other onboard echosounders This compact unit - measuring only 43 X 43 X 35 - uses Digital Signal Processing (DSP) technology to deliver accur..