FS: G3 GOS for Polar RS800 watches

I've used this maybe 3-4 times and it works fine, I just always forget to take it with me. It works with the RS800 series watches, might be compatible with other Polars but I am not sure.

New they are $139.95
http://www.amazon.com/Polar-GPS-Speed-Distance-Sensor/dp/B000VRACYG...

Selling mine used for $85/shipped.

G3 and strap only, I may still have the documentation for it. Ping me if interested.