How to Use: 1. Unscrew the cover at the bottom of the main unit of the product. 2. Insert the 3 batteries in the direction of the +/‑ poles of the battery slot and plug them back to the bottom of the product in the direction of the arrow of the battery slot and tighten the cover. 3. Put a gauze on the product host. 4. Press the power switch of the product, and then align the gauze to the mouth. 5. Open your mouth and align your teeth 6. The scan results can be viewed by mirror reflection (the plaque area is red. Please carefully check the health of the incisors, alveoli, and the back of the teeth). Specification: Item Type: Dental Plaque Detector Material: ABS Battery: 3 AAA batteries (shipped without batteries) Display mode: Assist eyes to identify plaque (red is the plaque area) Function: Identify dental plaque to distinguish the degree of tooth cleanliness. Package List: 1 x Dental Plaque Detector