This document introduces a product called HD-3, which is a compact and easy-to-use drum set. The product features a rich and wide variety of sounds, designed for use with all styles of music. It also has the ability to enjoy playing on your own, using headphones without worrying about others hearing. Additionally, the product can be connected to external audio sources, allowing for playing along with audio players, etc. When using the product, it is important to correctly connect the blue and brown wires of the power cord and select the appropriate drum kit. Please refer to the document for more details.