TS TAC-SKY Physical Noise-canceling Hearing Protection Headset Silicone EarmuffsDescription: 1 . Physical noise cancelling headphones , suitable for use in noisy working environments to protect the ears from harmful noise . The headphones do not require batteries and can be used directly after putting them on. 2 . The earphones are designed with a special cavity to form a good airtightness and block external sound waves from entering the ear . The headpiece is ergonomic and comfortable to wear without putting pressure on the