Item No HSP-109370 CNC-machined premium-quality aluminum set-up wheels for electric and nitro 1/10 touring cars allows for perfect, precise and repeatable set-up adjustment and tweak correction. Eliminates the errors inherent in using standard rubber tires or foam tires. Precision-machined to exacting tolerances, each alu set-up wheel in a set is perfectly matched.   When checking tweak on a rubber-tired touring car, using standard rubber tires typically gives non-precise and non-repeatable measurements. Rubber tires are never perfectly rounded, so when checking tweak one tire can lift earlier than another but this does not always indicate a tweaked car. Tire roundness and insert weight is different from one tire to the next. When checking tweak on a foam-tired touring car, the differences between tires are even greater than with rubber tires. Each foam tire has a different diameter after each run due to tire wear, making it impossible to check for tweak because the tires can give very misleading results. In this case the alu set-up wheels are the best tool for checking tweak.