http://www.insightavionics.com/tf500.htm
Anyone who does not have a fuel totalizer/computer, but does have a 430/530 needs one of these! Super cool fuel transducer that communicates with Garmin 430/530. I now have actual fuel flow in the fuel planning page of the 430. I have an accurate fuel computer, and no extra holes in the panel. Self calibrating. I've done probably 8 fill ups of 35+ gallons, and its been within 1/2 gallon every time. You set fuel added each fill up. Through the fuel planing page on 430/530, you get..... fuel to destination, fuel reserve at destination, endurance, mpg, fuel flow. Fuel reserve at destination looking thin? Pull the throttle and mixture back and watch your fuel reserve grow! You can also display fuel flow on main map page. Says it works with most ga gps units. $750 from Spruce. Highly recommended.

Does this unit only communicate with the 430/530 or will it with some of the handheld units as well?

gotta bump this. Almost a year and still think this is one of the coolest unknown instruments around. Totally happy with mine, don't think its ever been more than a gallon off, except for user error. Usually spot on. One simple transducer in your fuel line that talks directly to any gps with fuel flow info.

Fuel flow inflow is great. I use a Grand Rapids system in the experimental Bearhawk. It certainly improves fuel management accuracy.