Do a search on my name for a long post I did about my experience over 12 years with my Grover air horns, compressor, etc. , plus I've been to the Grover factory in east Los Angeles. The Grover compressor is not a well-engineered unit; mine broke down fairly frequently; the connecting rod in the compressor can be either steel or aluminum -- the aluminum one won't hold the bearings; Grover now has a policy of adding a $25. 00 surcharge to all orders under $200; this is to discourage dealers from placing small orders, but kills people like us who want the $29. 95 rebuild kit and have to pay an extra $25. 00 for it if we don't live within driving distance of east Los Angeles.