Stone makes sure that the rider stays safe even in situations where they have to pull the brakes suddenly. Most brakes function on the frictional force between the rim of the wheels and the brake pad. As such, periodic checking and changing of the brake pad from wear and tear is so important. Stone is a new type of brake pad that keeps track of the wear level.
Stone is designed with a holder and a brake pad that is constructed in 3 different coloured layers. As the brake pad wears down, coloured ink stains the rim of the wheel. The coloured line gets increasingly thicker, showing yellow, and then red. Yellow indicates that the brake pad is halfway done in its lifespan and red indicates that the brake pad has to be changed. While Stone does not differ from other brake pads in its basic function, it offers the extra benefit of risk advisory.