ADVANCED ULTRASONIC TECHNOLOGY: This sonic cleaner uses high-frequency 42,000 Hz ultrasonic waves to clean away stains and plaque from your Invisalign™ aligners or Vivera™ retainers in a non-abrasive manner. QUICK AND EASY TO USE: Fill the Invisalign Ultrasonic Cleaner Powered by Zima with water, put in your dental appliance(s), and then turn on. After 5 minutes, retrieve your clear and clean aligner or retainer. THOUGHTFUL DESIGN: Unlike other cleaners, the Invisalign Ultrasonic Cleaner's sleek, smooth, small and compact design won’t take up counter space while providing a deep clean to aligners or retainers of any size. The stopper lid fits securely and helps to minimize sound. Additionally, four Rubberized feet keep the cleaner from sliding on your countertop.