The Pro Ears Ultra Series advantage is the great comfort and noise attenuation with a Pro Ears warranty. The Ultra Pro Series has a NRR (Noise Reduction Rating) of 30 and the Ultra Sleek Series has a NRR of 26. When situational awareness is not as essential to mission accomplishment. A great pair of passive ear muffs are the most effective means to protect your hearing. Ear plugs can be effective only if they are properly inserted in the ear. A comfortable,well designed pair of ear muffs can protect your hearing for years to come. Our reliability gives you the confidence to be your best. We believe in our passive ear muffs so much we have provided the longest, most comprehensive warranty in the industry.