Profile: Minnesota Rubber and Plastics provides precision made rubber & plastic components and assemblies. We serve the appliance, agricultural, computer and food/beverage industries. Our automotive air filter gauge features a liquid silicone rubber diaphragm. Our butterfly valve regulates radiator coolant flow from the engine to the passenger compartment heater core. Our thin-walled diaphragms are used in electrically actuated indicator gauges in trucks and automobiles.