NoiseBuster PA4100 Behind-the-Head ANR Safety Earmuff
All noise-reduction earmuffs are not equal. Conventional passive earmuffs cannot protect you against low-frequency noise.
Passive earmuffs provide good protection in the mid-range and high frequencies. In comparison, NoiseBuster extends the performance of its passive 26NRR with an additional level of noise reduction—up to 20dB--in the low-frequency range that passive can’t touch. So, if you work around motors, engines, generators, fans, vacuums, blowers, etc., you need the additional protection of a combined passive/active noise reduction solution.