Those with a MM-2 Natural Gas Fitting License are able to install, alter, repair and service natural gas piping and fittings and incidental controls and control wiring, pneumatic control systems, excavating, trenching and backfilling. Includes installation of hot water systems exceeding 30p.s.i. or 400,000 b.t.u/hour input; steam and hot water boilers; and warm air heating systems such as chimney connections, flues, refractories, burners, fittings valves, thermal insulation, accessories and incidental piping; warm air appliances and other listed gas appliances. We create these self-practice test questions module referencing the concepts and principles currently valid in the exam. Each question comes with an answer and a short explanation which aids you in seeking further study information. For purpose of exam readiness drilling, this product includes questions that have varying numbers of choices. Some have 2 while some have 5 or 6. We want to make sure these questions are tough enough to really test your readiness and draw your focus to the weak areas. Think of these as challenges presented to you so to assess your comprehension of the subject matters. The goal is to reinforce learning, to validate successful transference of knowledge and to identify areas of weakness that require remediation.