Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 10980963 | Cloth respiratory mask | David Groll, Ronnie E. Mahofski, Eric S. Nachreiner | 2021-04-20 |
| 10814085 | Airtight mask seal | David Groll, Alexander C. De Poix | 2020-10-27 |
| 9981104 | Full face cloth respiratory mask | David Groll, Ronnie E. Mahofski, Eric S. Nachreiner | 2018-05-29 |
| 9308343 | Respiratory mask with disposable cloth body | David Groll, Ronnie E. Mahofski | 2016-04-12 |