Toilet Flush Sound Generator, Sound Effect Device, Sound Masking, Automatic Human Detection, Micro SD Card Compatible, Battery & AC Adapter, Wall-Mounted, Water-Saving ECO Melody 1. Automatic sensing function. When you enter the toilet, the temperature difference created by a person walking will activate the device, and music will begin to play. This creates a pleasant atmosphere. If not needed, you can turn off the automatic sensing function. (The sensitivity of this sensor is adjustable.) 2. Manual sensing function. You can manually operate the device to play music or extend the music when sitting on the toilet seat. You can also switch to music on the memory card with a hand gesture. (Please refer to the instruction manual for details.) 3. Can be used with either AC power or battery power. An AD-DC adapter is also included. Four AA batteries can be used for 7000 cycles. (Batteries are not included in the package.) 4. The device itself has four types of music: running water sound, birdsong, toilet flushing sound, and light music. You can import music onto a memory card. For those seeking better sound quality, you can connect to audio equipment via AUX. ※ Only opened for inspection. 82