Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5720280 | Attenuator for use with respirators | Gerald V. Elstran, Robert J. Mattila | 1998-02-24 |
| 5592935 | Positive/negative air pressure adaptor for use with respirators | Gerald V. Elstran, Robert J. Mattila | 1997-01-14 |