Innovative style tire chock. May be used for pit bikes to full size dirt bikes. (Accepts 8 to 21 inch wheels.) Maximum tyre width : 130mm (5.2 inch) Folding design saves space. (Height is 135mm ( 5.4 inch) when folded.) Accepts mini wheels (Up to 12 inch) even while it is folded. Self lock function prevents arm from opening up unexpectedly from folded position.