Review on Kawasaki Ninja 400 Z400 Slip-On Exhaust System Including Muffler For Improved Performance - Compatible With Models From 2018, 2019, And 2020 by Tony Hanson

I bought this exhaust at $70. This thing is A+ I am really impressed with it! I'm not sure if they updated the down-pipe diameter because mine fit snug but smooth, there was no need for pipe extenders or mallets anywhere on this install like mentioned in previous comments. I was able to line up the exhaust and secure it in about half an hour or so with a 10mm socket wrench and a pair of pliers. Fair warning the package did not come with instructions but its pretty simple to figure out. The springs are sturdy however not terribly difficult to stretch with some basic pliers. The sound is terrific, I smiled when I first turned it over with the new pipe, has a very deep non-lawn mower-y sound. I preferred to take the baffle out because the bike does not sound like a 400 when you do so, it sounds MEAN. Overall 5 stars on the first impression!