Enjoy hearing protection and entertainment using the 3M WorkTunes Connect Wireless Hearing Protector with Bluetooth Technology. It combines a modern, comfortable design with Hi-Fi sound quality. This innovative hearing protection lets you conveniently make and take phone calls while you're on the job. These ear-protective headphones allow you to stream the entertainment of your choice from your smartphone or other mobile device while providing ear protection in noisy environments. Low-profile, lightweight design is crafted with style in mind. Built-in comfort features, such as soft ear cushions and a hat-compatible, low-pressure headband, are excellent for extended wear. Safe Volume control technology allows increased volume yet corrects to maintain safe levels over an eight-hour workday. Audio assist technology provides setup and operational guidance without having to remove the headset. NRR 24 earmuffs require two 1.5-Volt AA batteries (sold separately).