This numbered 10-pack is for shoppers who want a real boar bristle toothbrush rather than a conventional soft nylon brush. Boar hair is a natural bristle that is firm with a stronger-cleaning traditional feel. The bamboo handles are numbered 1 to 10 and keep this a plastic and nylon free format. If you prefer a softer feel, our Soft Nylon bamboo toothbrush is the better choice. HARDNESS: Boar bristles are firm and suit shoppers who prefer a firmer brush and strong cleaning. PLASTIC AND NYLON FREE, NUMBERED: A natural bristle boar hair head on numbered bamboo handles 1 to 10, with no synthetic nylon filaments, shipped in a simple paper box so a family can tell brushes apart. SOAK BEFORE FIRST USE: Boar bristles naturally vary in length and are trimmed to an even length, so a small amount of loose bristle dust or short fibers may remain from trimming and packing. Before first use, soak each head for a few minutes in warm water around 104°F (40°C) to rinse it and soften the bristles. REAL NATURAL BRISTLE, SECURED MECHANICALLY: Boar hair is a real animal bristle, secured mechanically rather than melted into the head like the thermoplastic nylon used in some brushes. Because of this, a few loose hairs can release during the first uses or over time. This is normal for real animal hair. NATURAL ODOR: Real animal-hair bristles can carry a mild natural smell at first; soaking and rinsing reduces it. CARE AND REPLACEMENT: Rinse after each use, store each brush upright and let it air-dry fully, and do not keep it wet in a closed container. Replace every 3 to 4 months, sooner if the bristles shed excessively. SIZE: Each brush head is sized for a typical adult mouth.