The DST810 is the real technical centrepiece of this pack: a single multisensor transducer that reads depth (to 330ft), boat speed through the water (at a fast 5Hz update rate), water temperature, and - via its internal attitude sensing - heel/trim and pitch/roll data, all fed to the NMEA 2000 network and the GNX 20 display. It operates at 235kHz with a 10x44 degree fan-shaped beam, and supports Bluetooth calibration directly through Airmar's Cast app rather than needing a manual calibration procedure at the helm. Power consumption on the displays is very low - 350mW in daylight, 400mW at night with backlight - a real consideration for sailboats running on a limited battery budget. This is a complete, ready-to-install sailing instrument upgrade for a boat that doesn't yet have a proper wind/speed/depth package, or is replacing an ageing one.