This is a Modine HD45 (45,000btu) propane fired heater. It is forced air and direct vent like a furnace so no combustion fumes will enter your garage. You can safely run this heater for days and not worry about C02 or nasty smells like you do with a kerosene heater. I used this heater to heat a very large 2 car garage and on below zero days I was working in a T-shirt within 15 minutes of turning the heater on.
The heater includes about $200 worth of stainless steel vent tubing including a stainless through wall bushing. This heater can be converted to run on natural gas by purchasing a $20 orifice.
The heater has less then 200 hours of use on it and is in like new condition.
I spent ~$700 for this setup.
$450 firm.