FULL COMPATIBILITY: Compatible with FW507/508/515/551/917/959/D7/D8/D3/D1/2011; Compatible with SG E9/507/515/575/909/917/949/958/908/610/659/719/910; Compatible with HP126A/HP150A; Compatible with Dnsly TB5; Compatible with Fairywill/Sboly/ATMOKO/Teeteck. (NOTE: NOT compatible with Fairywill E11/2001/2081/2205/2209/921) DUPONT QUALITY FIBERS: The bristles are made of DUPONT nylon, a professional, high-quality bristle material for toothbrush heads. The bristles offer the perfect balance between soft and firm, ideal for cleaning sensitive areas and effectively removing food particles and plaque! EFFECTIVE AND CLEAN: W-shaped bristles are designed to conform to the topography of your teeth, ensuring the brush head reaches every area, thoroughly cleaning your gums and easily removing hidden plaque! The bristles fade to remind you when it's time for a replacement. ROUNDED BRISTLES: The bristle ends are rounded through a polishing process for safety and gentleness. Protecting your gums, these replacement heads are extra gentle and comfortable on teeth and gums compared to standard replacement brush heads. High-reliability bristle planting ensures bristles won't fall out. GREAT VALUE: 10 replacement brush heads, vacuum-packed at an unbeatable price. Dentists recommend replacing your toothbrush head at least every three months. Our replacement brushes will last for months, even years. Makes a great gift for family and friends.