http://tinyurl.com/oyaqbdj
Noisebuster Electronic Noise Canceling Safety Earmuffs - Standard - PA4000Product Review
Click on the link for more reviews
Electronics cancel low frequency noise
Comes with sturdy carry case
NRR 26dB -- PLUS 20dB electronic noise cancellation
Can be used with portable audio
Over-the-head and behind-the-head use
