3M earmuffs. They have very high sound insulation and noise reduction. Also ideal for noise対策 in construction. Used twice, no longer needed, so selling. Specifications/Standards/Manufacturer: PELTOR ・Noise Reduction Rating: 30dB ・Type: Headband type ・Weight (g): 295 ・Color: Black ・Size: Free ・With box (slightly scratched) ・With instruction manual Product Description PELTOR Earmuffs Optime3 "H540A" [NRR: 30dB] High-level noise reduction performance. POINT 1 High Performance The H540A is ideal for hearing protection in noisy environments. From noise protection in the workplace, such as factories, aviation-related, shooting, and motorsports, to sound insulation in various environments such as studying, reading, sleeping, and other noisy environments. Example: It provides almost complete sound insulation even during heavy machinery noise during construction of apartments, etc. POINT 2 Comfort and Fit The cushion part that touches the ears and head is made of a sponge layer, which effectively seals the ears and increases the sound insulation effect. In addition, the length of the wire connecting to the cup can be adjusted (slide adjustment type), and it can be moved up and down about 35mm on both sides. It can be used to fit the size of your head. Noise Reduction Rating The higher the number, the higher the sound insulation performance of the protective device. (Example) When working in an environment with a noise level of 105dB To reduce it to 80dB, you need noise protection with a sound insulation performance of 25dB or more. 105dB - 25dB = 80dB This is a representative 3M product used by construction workers. Earmuffs Noise reduction Sound insulation Earmuffs