FS: Ball 501 electronic audio variometer

Ball model 501 audio variometer for sale. Fits standard 3 1/8"
mounting hole. Operates on 9 volt battery (battery included). Has
total energy port. 10 knots scale. Manufactured in March of 2000.
Has a volume control, also the audio function can be turned off. This
vario is in excellent condition. A stock picture of the variometer
can be seen he http://www.visi.com/~jrc/501.jpg

$299.00 US dollars (or best offer), plus actual UPS shipping costs.
If you provide me with your Zip code I can obtain a price for
shipping. I will ship within the United States only. Contact via
email; .