M91/L - length = 470 M91/H - length = 430
| U | Frequency | Sound level [dB] | Symbol | Order No. |
|---|---|---|---|---|
| 12 V | High 390 Hz ± 5% | 117 | M91/1N/12V HIGH | TFK-41AT |
| 12 V | Low 340 Hz ± 5% | 117 | M91/1N/12V LOW | TFK-42AT |
| 12 V | set H+L | 117 | M91/2/12V | TFK-43BT |
| 24 V | High 390 Hz ± 5% | 117 | M91/1N/24V HIGH | TFK-44AT |
| 24 V | Low 340 Hz ± 5% | 117 | M91/1N/24V LOW | TFK-45AT |
| 24 V | set H+L | 117 | M91/2/24V | TFK-46BT |