OTTO Engineering NoizeBarrier Micro Black. The dual-mode NoizeBarrier earplugs offer active hearing protection as well as hearing enhancement for extremely effective sound localization and detection. Specifications for OTTO Engineering NoizeBarrier Micro: Manufacturer: OTTO Engineering NRR: 28 dB Quantity: 1 Size: Micro Color: Black Included Accessories: Charging Case Condition: New Battery Life: 16 hours Water Resistance Level: IP67 Headphone Style: In Ear Gender: Unisex Features of OTTO Engineering NoizeBarrier Micro Up to 40 dB of impulse noise protection Up to 15 dB adaptive noise attenuation Hearing enhancement mode amplifies soft sounds up to 5X Natural hearing for safe sounds Accu-Technology high-definition sound quality One-button touch pad 2-mode operation NRR: 28 dB(Foam Tips); 23 dB (3-Flange Tips) Frequency Response: 40Hz - 16kHz Transducers: Balanced armature receivers (speakers) Wide bandwidth Low-noise MEMS microphones Battery Performance: Earplugs - Up to 16 hours; Charge Station - 20 earplug charge cycles Earpiece and case IP67 water resistant Charging status LCD panel 1-year warranty Package Contents: OTTO Engineering NoizeBarrier Micro Contained within OTTO Engineering V4-11029: NoizeBarrier Micro Black