This document is the safety precautions for DR-S1622 16 Channel Digital Recorder and DR-S0930 9 Channel Digital Recorder. The main contents are about the installation, use, cleaning and maintenance of the equipment. They include prohibiting the equipment from being placed outdoors in the rain, heavy humidity or dust, prohibiting the equipment from being exposed to water or humidity, prohibiting the equipment from being placed in a rainy or humid environment to avoid fire or electrical short circuit.