This type of sprocket differs from the traditional ones since the two semisprocket are designed to ensure a perfect coupling once assembled on the axle, thus eliminating the empty space between the two parts typical of the 428 standards sprockets.
This means that during assembly it will not be necessary to distribute the clamping load to align the closure, and once assembled the load applied by the sprocket to the axle out to be homogeneous, avoiding possible axle deformations and ensuring a perfect grip.