I always assume Woodcraft to be a premium brand. I installed these front sliders on my 2021 ninja 400 tonight and it was very frustrating. The side of the axle with the cotter pin (with the nut that you torque) would absolutely not work. We installed it correctly, aligned all holes correctly, and it would not go through. I removed the puck and was test fitting the cotter pin on just the axle nut by itself. It went through completely fine. As soon as you put the "inner" portion of the woodcraft puck over the axle nut, the cotter pin would not go through. You could get it halfway, and then it would get hung up/misaligned. So either I got a bad cotter pin, or the holes did not align properly on the inner portion. We had to take a grinder to the back side of the cotter pin to give it an angle, and that allowed us to get the pin through. I don't think that should be necessary on a premium product. I watched the videos on STG, and his gave him no such issue. 3 stars due to my frustration. Maybe they'll reach out and make it right?