Airmar B117 50/200kHz Bronze Low Profile Depth OnlyAirmar B117 50 200kHz Bronze Low Profile Depth Only B117 DO 2 The Airmar B117 features a 50 200 kHz, dual frequency, single ceramic element in a low profile bronze housing. The nearly flush design minimizes drag with only 5 mm (2 10") extending outside of the hull. Compatibility: AutohelmST 50 Features Depth only or depth and temperature 600 W Dual frequency elements: 50 kHz with a wide 45 beam for performance to 353 m (1200') 200 kHz with a 12 beam