I am a NATE certified HVAC tech and have gone through schooling for oil burning heaters like this one, I am currently working for a camper van conversion company and install the higher end Webasto and Espar heaters, I also live full time in a van in the mountains of Colorado so I believe I am qualified to post a review of this heater.I purchased and installed one of these heaters in a 98 Chevy Suburvan about 4 months ago and as mentioned I professionally install the higher end heaters, and this HappyBuy heater is almost identical to Webasto and Espar in every aspect except for price. I was initially timid about purchasing a _hinese knockoff, especially at such a low cost. But I have been nothing but impressed with this heater. The heater is easy to install and there is a wealth of knowledge on Youtube for anyone who is inexperienced with this type of equipment. The _hermostat is relatively easy to use, the instruction manual is mostly gibberish but you can find most of the info you need online. I am a little bit bummed out that the _hermostat is not actually a thermostat, it does nothing to regulate the temperature, it_ either on or off, higher or lower heat. But I am impressed by the amount of control that the user has over the unit through the thermostat. $2,600 Espar Heaters require an $600 aftermarket _igh Altitude kit which just changes the oil pumping frequency to accommodate for less atmospheric Oxygen, however the HappyBuy Knock-Off heater allows the user to change the pump frequency through the thermostat, among many other cool features. Heads up, if you are gonna use it at higher altitudes, make sure your vehicle doesn_ get buried in snow to the point that it restricts the intake of combustion air, you want really good airflow underneath the vehicle at all times.I assumed that at less than $150, HappyBuy would eliminate some of the features that help the heater to operate safely and ensure longevity. But I was wrong, the heater goes through the exact same start up and shut down cycle as the higher end models, and the HappyBuy Heater has all of the key safety features that any oil or gas heating system should have. Be careful though, the keychain remote control works from much farther away than you would think, I have accidentally turned the heater on from over 150 meters away, while inside of a building, I am amazed at how powerful the signal is.I would personally recommend throwing away the cardboard duct tubing that comes with the heater, the high output temperature of the heater causes a powerful cardboard aroma to fill the vehicle, it doesn_ burn the cardboard, it just gets it warm enough to be stinky. I used 3 metal round ducting from the HomeDepot to avoid the _aking cardboard smell. One final complaint that I have with all of the diesel parking heaters, is the fact that they do not have an emergency kill switch. Every single flame driven heat system should have a way to immediately and safely shut off the burner(s). I installed a