"UHD" scanning sonar is Garmin's higher-resolution successor to its original ClearVu/SideVu technology, rendering noticeably sharper structure and fish detail at close-in ranges than standard-definition scanning sonar, particularly useful for picking individual fish out of structure rather than seeing one blurred mass. Being a thru-hull pair rather than a single transom-mount unit, this is intended for permanent installation on larger boats where a clean, faired hull penetration is preferable to a transom bracket, and running two units (port and starboard) gives fuller coverage across the boat's beam than a single centreline transducer alone. It's a direct upgrade path for boat owners moving to Garmin's UHD sonar generation from an older standard-definition ClearVu/SideVu setup. Garmin's UHD-series transducers are compatible with its current GPSMAP and ECHOMAP Ultra chartplotter lines, and a port/starboard pair like this is commonly run alongside a forward-looking Panoptix transducer for full sonar coverage.