Key Features
- DC-1A noise-canceling dynamic microphone
- Soft, ribbed-design foam headpad
- 7.62-meter straight cord with SC-267 plug
- Corrosion-resistant chrome headband
- Certified noise reduction: 26 dB NRR
Attenuation by Frequency
| Frequency (Hz) | Attenuation (dB) | Std. Deviation |
| 125 | 22.4 | 3.2 |
| 250 | 25.5 | 3.2 |
| 500 | 30.3 | 3.0 |
| 1000 | 33.3 | 2.2 |
| 2000 | 34.1 | 2.5 |
| 3000 | 39.3 | 2.6 |
| 4000 | 39.9 | 2.4 |
| 6000 | 38.7 | 2.5 |
| 8000 | 38.3 | 3.5 |
NRR Calculation
The NRR (Noise Reduction Rating) is a federal standard for measuring noise attenuation effectiveness:
- A higher NRR indicates greater protection
- Estimated noise level = Ambient noise level - NRR
- Example: 100 dB ambient - 26 dB NRR = 74 dB protected
For environments with frequencies below 500 Hz, use C-weighted measurement
Usage Instructions
- For over-the-head use: fully open the headband adjustment and place the protector over the ears
- Adjust the headband until the top padding rests comfortably on the head
- Adjust the ear cups slightly up/down or sideways for maximum attenuation
- For behind-the-head or under-the-chin use: fully close the headband adjustment and follow the same procedure
- For prolonged use, the additional support strap (P/N 10370G-03) is recommended
- Eyeglasses with thin temples minimize noise leakage
Maintenance
- Clean regularly with mild soap and water
- Do not immerse in water (especially on models with communication)
- Do not alter or modify the protector
- Replace immediately if cracked or damaged
- Avoid prolonged storage in direct sunlight or high temperatures
- Replace pads and seals when they lose elasticity or softness
Warnings
- The NRR does not guarantee complete protection in all situations
- Do not use in impulsive noise environments (such as gunfire) without additional protection
- The use of eyeglasses with thick temples reduces effectiveness
- Consult a physician if exposed to loud noise for long periods
- The NRR does not account for factors such as durability or comfort
