I have a new Humminbird transom speed sensor for sale. It is Humminbird part #730021-1. Package says it fits all Matrix, 100, 300, 500 700 and 900 Series. Measures speed from 2 to 70 mph. I opened the package because I bought it separately from the depth finder and didn't realize the depth finder came with a speed sensor. These sell for $40 new. Since the package is opened, I will sell it for $20. I am in Uniontown in Stark County. Name is Roger. Cell phone is 330-903-0803.