Airmar B275LH-W Bronze Chirp Thru-Hull f/Garmin w/12-Pin ConnectorB275LH W Bronze Thru Hull for Garmin with 12 Pin Connector Get more coverage under your boat with Airmars unique wide beam, low and high frequency, Chirp ready B275LHW. The high band operates across a frequency range of 150 to 250 kHz and has a fixed 25 beam for all frequencies, which results in superior resolution. The constantly wide beam provides twice the coverage and clear fish arches on the display compared to most high frequency, narrow beam