| 333310 |
Magnifying glasses (except corrective vision-type) manufacturing |
| 333310 |
Magnifying instruments, optical, manufacturing |
| 333310 |
Mail handling machinery, post office-type, manufacturing |
| 333310 |
Mechanisms for coin- or card-operated machines manufacturing |
| 333310 |
Microfiche equipment (e.g., cameras, projectors, readers) manufacturing |
| 333310 |
Microfilm equipment (e.g., cameras, projectors, readers) manufacturing |
| 333310 |
Microscopes (except electron, proton) manufacturing |
| 333310 |
Microwave ovens, commercial-type, manufacturing |
| 333310 |
Mirrors, optical, manufacturing |
| 333310 |
Mop wringers manufacturing |