This document is the user manual for the Casio electronic instrument CTK810/WK110CH1A Ch. It includes safety precautions and guidance for using the instrument. The document introduces safety symbols and precautions for using the instrument, such as danger, warning, and caution. It also mentions some things to be aware of when using the instrument, such as the use of alkaline batteries, actions to take when there is smoke, odor, or overheating, precautions for using AC adapters, battery usage precautions, and the prohibition of disassembling and modifying the instrument.