Arrowmax have added a differential hardness checker to their electronics line up. The small and compact device allows to measure the hardness of both gear and ball differentials which makes diff setup easier and more precise. Other than checking the differential setting the tool can also be used to pre-warm diffs before a run, which makes for better consistency. The device features a 5-digit decimal display, it is housed in a sturdy case and utilises a built-in Micro USB port for charging. The diff checker comes with both a standard outdrive insert and a 7mm nut driver adapters for touring car usage. Optionally available is a set of 1/8th buggy and GT adapters.