This is my 2nd laser. I bought the first one 2 years ago used and its still working good. Mirrors were fairly easy to align. I bought a new water pump and compressor for air assist burning. I didn't use the exhaust fan because it pushes the air, Best to get and inline 100 to 200 cfm pipe fan and mount it as close to the end of the run as possible. I'm hoping this one is as reliable as the other one.