The 3M Peltor Optime III helemt attachment earmuffs is a high performance hearing protector and has been developed for use in extremely noise environments. The protection is based on a technology with a double casing minimising resonance in the holder casing, maximising high-frequency attenuation. An acoustic connection between the inner volume and the volume between the casings in its turn provides low-frequency attenuation. The 3M Peltor Optime III sealing rings are broad and filled with soft plastic foam for the best fit and low contact pressure, the earmuff stands for effective protection and highest comfort for the wearer. For use with the following helmets: JSP MK7, MK8 & EVOLITE, PROTECTOR HC300EL, HC710, MSA V-GARD, and SUPERV-GARD II.