ISOtunes Sport DEFY Slim is an ultra-comfortable electronic earmuff, featuring superior protection and environmental awareness. With active gunshot noise suppression, Bluetooth compatibility, and a background noise-dampening microphone, DEFY Slim allows you to align your sights with ease without sacrificing your safety. TACTICAL SOUND CONTROL: Proprietary technology that amplifies sounds you want to hear up to 8x their natural volume, while still protecting you from harmful gunshot noises in under 2 milliseconds. 21 NRR NOISE ISOLATION: Most gunshots register between 150 – 170 decibels, which can quickly damage your hearing. Combat those dangerous noise levels and shoot safely all day long. ULTRA-SLIM DESIGN: At just 310 g, this ultra-slim muff weighs 100g less than other leading earmuffs. Enjoy all day performance and comfort, while aligning your sights with ease. ALL DAY BATTERY: Up to 25 hour battery life with two AAA batteries (included). IPX4 DURABILITY: Stands up to the toughest conditions with IPX4 water, sweat, and dust resistance. NOISE-ISOLATING MICROPHONE: Keep in touch with clear communication in loud environments. ISOtunes Sport DEFY Slim comes with 2 AAA batteries and an auxiliary cable.