3M 2" X 1.4" X .52" Rechargeable Noise Indicator

3M Noise Indicator NI-100 provides easy, durable noise level detection by alerting users to potentially dangerous noise levels and helping identify areas where hearing protection may need to be worn. Users simply clip the Noise Indicator to a shirt or jacket; its LED light delivers a clear indication when noise levels exceed a potentially hazardous threshold. -Red Flashing LED indicates noise levels are above 85 dBA and hearing protection may be required. -Green Flashing LED indicates noise levels are below 85 dBA and hearing protection may not be necessary.