A SI-TEX AIS transceiver, used once for 3 weeks. Like new, in original package with all paper work. It was purchased in November 2023 for one yacht delivery trip to communicate with tugs and barges, oil field supply boats on the ICW Gulf of Mexico. Used 3 weeks and removed. It's a Metadata MDA-5H Class B/SO AIS. It connects with a PC plotter program via USB cable, and with any chartplotter/radar via 2 wires. I connected it to my ASUS laptop using a Maptech Navigator Pro charting progam, and to a Raymarine E120 Plotter/radar (15 years old) with no issues. Located in Stuart, FL