UNIOR: Product featuresMaterial: construction steel, stainless steel and PE-polyethylenePrecisely manufactured tools enable simple checking of wheels with dimensions from 16 to 29 inch, with or without tire.How to use the tool:The true checking tool is a tool designed to check the axle symmetry between the hub and the wheel rim. First we set an appropriate distance between the slides according to the wheel size. We 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 we fix the rest with a screw and check the other side of the wheel. This enables us to see if the nave is centered according to the rim. If the wheel is not centered, it needs to be trued up.