http://cgi.ebay.com/2-4G-0-1W-wirele...QQcmdZViewItem
When you look at the ad it says .1 watts but it's actuall 1 watt or 1000 mw.
If you strip the metal case off it and bypass the regulator so that you can run it off your plane's battery, it's not very heavy at all.
I have one of these and with the stock antenna I get about a half mile range. I have one receiver that I put an sma connector and gp patch antenna on and with that I get over a mile.