I bought the gps receiver with the heading sensor only to find out that it doesn't work with my unit. I have the box and everything that came with it. I had to open it to try it. It has been selling for 200.00 but i will take 175.00 shipped U.S. only. Make sure this will work with your unit before you buy. Mine was listed as compatible until after i bought it then HB removed my unit from the list....788ci