The biggest change Kevin made on the K4 hangars was an updated bushing seat: it creates extra lean turn. Aera trucks have been designed as a light weight truck for all speeds and all locations.
Not only have they been on the most racing podiums, and won more World Championships, they also have kicked butt on most freeride and slopestyle events around the world.
They are the choice of champions.
K4 trucks was designed with the input of multiple riders and the Aera Team. They were searching for the Answer = more lean more stability.
These trucks are on the 46 degree baseplate, most suited for racing and high speed. They do still have enough turn to let you get steezy while freeriding.
These are super limited, the last of the K4's in Australia...and maybe the world.