I bought this set of levers for my 2021 Kawasaki Z400, hoping they would work since it is so similar to the Ninja 400. Installation of the brake lever was a breeze. The clutch lever was more difficult - you need to really push the plastic bit on the cable into place, and check very carefully to make sure nothing is rubbing against the cable. It helps to get it into your garage (i.e. in the dark) and use a flashlight. On my husband's Ninja 400, he didn't have this issue. Overall, I'm very happy with them! Love being able to adjust to where the levers are comfortable for my hands. Figured I would share in case any other z400 owners need this information :).