Professional Noise-Canceling Earmuff:(New Version 2021)OPSMEN M31-MOD3 is an electronic pickup and noise-canceling headphone during daily training.Suppresses harmful noise above 82 dB.Noise reduction rating + NRR22. Super Fast Attack Time：When wearing headphones, you can feel the fast attack wave (such as when the gun is firing). The super fast attack time is less than 1 ms, which can instantly suppress the ambient sound and protect the user's hearing from damage. 360° Full Environment Perception：M31-MOD3 can enhance weak sound in the environment and track human voice to restore and optimize, with 3-levels adjustable sound effect gain function to enhance hearing.Improves the clarity of conversation and the surrounding environment alertness. Humanized Design:Adjustable headband with three different sizes. Suitable for men and women.The design is ergonomic, fits the ears better, and provides more professional noise reduction protection.Foldable earmuff design. Suitable for Many Occasions：Such as shooting,hunting,chainsaw,machining or in a noisy environment.M31-MOD3 adopts waterproof and anti-impact technology, waterproof in accordance with IPX-5.Suitable for various harsh environments.