oil, gas, and air filters for motors and engines; Aftermarket automobile engine exhaust systems comprised of pipes, collectors, mufflers, and particulate traps; Air filters for automobile engines; Air filters for mechanical purposes; Blades for power saws; Blades for power tools; Filter elements for fuel filters; Oil filters; Oil separators; Pneumatic air preparation equipment, namely, airline filters, lubricators, and regulators, all being parts of machines