Description: The ultrasonic cleaner is a microprocessor-controlled device that uses ultrasonic or high frequency sound waves to clean jewelry and other delicate items. Ultrasonic cleaning is based on the cavitation effect caused by high frequency ultrasonic wave vibration signals in fluid. Microscopic bubbles that expand and rapidly collapse cause cavitation, which creates an effective cleaning action on the surface of object being cleaned. Additionally, the bubbles are small enougugh to penetrate even microscopic crevices, cleaning them thoroughly and consistently. Package included : 1 x 3L Ultrasonic Cleaner1 x Plug1 x User Manual1 x Cover1 x Basket Note: During cleaning, the"ZiZi" noise is normal.Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.