I purchased three of these unit, 2 12Volt and 1 24 volt and could not be any happier. I mounted the units on the roof of some older American Cranes. The install in my particular case only took about 2 and half hours to install from start to finish. The instructions are straight forward and it simple. The units came with everything you need to complete the install except freon. I did have to install a second alternator on my 24 volt system due to the one on it not producing enough power. The systems do an amazing job at keeping the cranes cool which are just like ovens with nothing but a sheet metal wall between the operator and the engine. For the money you cannot beat it these are awesome units! I would not hesitate to purchase more or recommend them to anyone else in need of a self contained AC system. I also cannot say enough good things about Scott and the guys at VMACS when it comes to there customer service and reliability, if he says he has it or can get it in a timely manner he does!!