I got an e-mail back from the web site, they said it was just for the big home style propane tanks with a sender.
So, that saves me some money.
Ozz
'07 3400RL 2nd RTU
2 Golf Cart batteries 1500 watt inverter
Honda 2000 Generator, 2nd one and twinning kit coming
Maytag's with 220 Dryer
Stationary domed Sat. dish
LCD 12 Volt Amp gauge
LCD Tank Monitor
3 added 120 volt outlets
On Board Air; 12 Volt Viair 450C compressor
2006 Ford PSD 4x4 Off Road Lariat
Hadley Air Horns
Truck inverter with 110 volts for laptop
Color Backup Camera
Awning lock