3M Pro-Grade Noise-Reducing Earmuff, NRR 30 dB, Lightweight and Adjustable 3M? Pro Grade Earmuff offers superior comfort and protection. The 3M? Pro Grade Earmuff is designed to be a high noise reducing/protection earmuff. Adjustable, vented headband design reduces heat build and improves comfort when worn with hats. Part of the 3M? Pro Series Safety Products line that was designed for the way pros think, the way they shop and the way they work Features Our #1 noise-reducing earmuff Noise Reduction Rating (NRR) of 30 dB Helps protect against harmful noises Steel wire headband with rubber overmold design for durability and comfort USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.