Howard Leight by Honeywell Impact Series Sound Amplification Hard Hat Electronic Earmuff (1010632) Built-in directional microphones amplify voices, alarms and other ambient workplace sounds to a safe 82dB, providing more natural listening and enhanced communication Actively listens and automatically shuts off amplification when ambient sound reaches 82 dB; earcups snap in place when you need them and swing back when you dont Compatible with a wide range of hard hats for optimal head and hearing protection; includes adapter for use with AO Safety, Bullard, Jackson, MSA and North hard hats Snap-in ear cushions allow for easy maintenance and replacement; includes 2 AA batteries plus 3.5mm audio jack and connection cable for personal listening devices Noise Reduction Rating 21; Recommended industries: aviation, farming, construction, lumber, steel, transportation, military/law enforcement, manufacturing, sporting, DIY projects, general contracting