This endorsement is required to haul any liquid or gaseous materials in a tank or tanks having a capacity of 1,000 gallons or more that is either permanently or temporarily attached to the vehicle or chassis. To receive this endorsement, applicants must pass a test The test consists of 20 multiple choice questions. Each question has four answer choices. To pass, the applicant must answer at least 16questions correctly. Test questions come from the Texas Commercial Motor Vehicle Drivers Handbook. Questions come from chapters covering: Driving Safely, Combination Vehicles and Doubles and Triples. The Tank endorsement can be used with the Class A, B or C CDL.