The Vertex(TM) NANO premium in-ear hearing protection provides all day comfort and protection. The custom micro-circuitry has 2 mode levels for standard and enhanced amplification with a less than 0.02 second reaction time to protect against dangerous impulse noises. Dedicated right and left plugs are each powered by ultra-efficient 312 zinc air cell for up to 120 hours battery life. Batteries included, plus extra bonus set of batteries. Hi-Low Sound Compression (85dB and 105dB), 5X Enhancement of Everyday Sounds, NRR 25, Sport Ear Hooks, Optional Corded Tether, Carrying Case, Rubberized Paint for Soft-Touch Feel. Mfg: Radians