I installed this header on my 2020 890 Duke R. There were no instructions in the box but it is not a complicated job. Fit and finish (welds) is excellent. I reused the stock gaskets at the primary ports but it would have been nice if they included some at this price point. A gasket was included on the collector to muffler junction. A big surprise was the weight - 1282g vs 1480 for the stock header. That's only half a pound difference, folks. One culprit might be the primary flange couplings - they seem to be steel rather than titanium and quite heavy. Further, all the connecting springs add up in weight as well. I have not dynoed my bike but seat of the pants (for what it's worth) suggests that power has picked up meaningfully throughout the midrange. And softness in the 4K to 5K range seems to have been reduced considerably - I note that the primaries on this header are markedly longer than stock. Regarding sound quality, my de-catted bike is so loud that one cannot detect a lot of nuance :-) It still sounds good to me.