Fully adjustable for small, medium and large head sizes. Lightweight polymer plastic construction. 25dB noise level reduction rating. Reduces hazardous noise to harmless levels within 5 milliseconds. Independent volume control for each ear. Battery life of up to 200 hours. With audio input jack for connection to two way radios. Ruggered durability. Suitable for shooting,hunting, construction, factory, motor racing, police or military use.