The refills for Proxabrush interdental brushes GUM have a diameter of 0.9 mm. They are particularly thin and conical, allowing them to pass through the narrowest spaces without forcing the passage. They have una antibacterial protection to prevent growth on the stems. Interdental brushes are essential for cleaning interdental spaces, removing dental plaque, and eliminating food debris stuck. The blue threads are made of monofilament nylon, ensuring safety and comfort of use.