So my 1 old gpr damper was leaking ever so slightly. I called customer service to explain my issue. The tech rep. explain is was a mild smal issue of a few tops not being made to spec. that did not fit the bottom quite right. Either way I sent it in, they fixed it free of charge and gave new oil and seal service to it for nothing. Got it back about 1.5 weeks later, and noticed a ding near a bolt hole. I was not happy about that and I knew it was not during shipping since it was well packaged. Either way, I called back again and said to send it back that they would fix it, and appologized. He thought it may have happened during shipping, but I told him the package showed up in good shape. Not all mangled. So one week later after I sent it back the second time, they shipped me a brand new unit! No more stupid red adjustment knob! I came with the black knob. I could not be happier.