| Number | Name | Date | Kind |
|---|---|---|---|
| D231613 | Sarber | May 1974 | |
| 3645354 | Kliewer | Feb 1972 | |
| 4420657 | Larkin | Dec 1983 | |
| 4634816 | O'Malley et al. | Jan 1987 | |
| 4754484 | Larkin et al. | Jun 1988 | |
| 4875233 | Derhaag et al. | Oct 1989 |
| Entry |
|---|
| HFD; 08/08/88; p 92; Panasonic Model WM-TH10 telephone headset. |