A combination overfill protection device, fluid level gauge, includes a service valve having a body defining a set of wrench flats, an input port, and a tank port wherein the overfill protection device has a float that rotates a shaft in response to a change in fluid level, the shaft transitioning the overfill protection device between opened and closed configurations and rotating a magnet within the service valve body proximate the wrench flat and wherein a gauge dial has a dial magnet housing sized to fit proximate to the wrench flat such that rotation of the magnet within the service valve actuates a dial magnet housed substantially in the dial magnet housing.