Garmin GT21-TH S/S Thru-Hull ClearVü & CHIRP, 600W 50/200kHz Traditional, 500W 260 & 455 ClearVü CHIRPGarmin GT21 TH S S Thru Hull ClearV & CHIRP is the ideal sonar solution for coastal and offshore anglers who demand traditional sonar plus CHIRP ClearV scanning sonar from a rugged stainless steel thru hull stem. Experience consistently clear and crisp fish arches with superior target separation and precise structure definition below your boat thanks to this high performance transducer. CHIRP ClearV element: 500 W power rating; operating frequencies