downhole drilling equipment, namely, drilling motors, transmissions, bearing assemblies, motor housings, and parts therefor used in the oil and gas drilling, production, and workover industries

repair and maintenance of downhole drilling equipment and parts therefor, namely, drilling motors, transmissions, bearing assemblies, and motor housings, used in the oil and gas drilling, production, and workover industries for others; rental of downhole drilling equipment and parts therefor, namely, drilling motors, transmissions, bearing assemblies, and motor housings, used in the oil and gas drilling, production, and workover industries