| Number | Name | Date | Kind |
|---|---|---|---|
| D254251 | Ward | Feb 1980 | |
| D317008 | Emmerling | May 1991 | |
| D319243 | Yamakawa | Aug 1991 | |
| D342739 | Atkin et al. | Dec 1993 | |
| D356088 | Jewitt et al. | May 1995 |
| Entry |
|---|
| Hong Kong Enterprise Jun. 1993, p. 551, Model 505, Cordless Stereo Speaker System. |
| Stereo Review, Dec. 1993, p. 32, Koss HD/1 Speakers. |