Garmin AIRMAR R109LMGarmin AIRMAR R109LM Garmin AIRMAR R109LM are a high performance, 2kW CHIRP thru hull marine transducer with a fairing block, designed for deep water commercial and recreational fishing. It provides both depth and fast response water temperature readings and is compatible with large boats (40 feet and above) with fiberglass, wood, or metal hulls Garmin AIRMAR R109LM Key Features Technology: Uses CHIRP technology (chirped, frequency swept pulses) to