Compressors and dryers designated as “checked” have been carefully inspected and test run by DUP. On request potential customers can take a look at the processor of their choice in operation on our premises. Alternatively, we can supply a video showing the test run. These compressors are delivered or handed over in working order. Compressors designated as “unchecked” are handed over or delivered in the condition in which we purchased them. In this case, they have not been checked by DUP for functionality and carry no guarantee.