The Pro Ear Revo muff is our child-size model of Pro Ears electronic hearing protection. Designed with a Noise Reduction Rating (NRR) of 25, the Pro Ears Revo protects your child's ears for the loudest environments while still amplifying quieter sounds for improved situational awareness. Constructed using dual circuit board technology, adjust the hearing and amplification levels separately for each ear to compensate for uneven hearing loss using the dual knob system. Pro Ears ensures that your child's ears are safe, but still able to listen to you. For the ultimate in Performance, Comfort and Reliability.