The true checking tool is a tool designed to check the axle symmetry between the hub and the wheel rim. First Unior set an appropriate distance between the slides according to the wheel size. They lean the middle rest against the nave axle and put the frame with slides nearer to the rim so that the slides touch the rim. Then they fix the rest with a screw and check the other side of the wheel. This enables to see if the nave is centered according to the rim. If the wheel is not centered, it needs to be trued up.
Material: stainless steel and PE-polyethylene
Weight supplement: manufacturer's specs