【High-Quality Replacement Brush Heads】 The P-HX-6064 model electric toothbrush replacement brush heads use US Dupont Tynex nylon bristles, effectively cleaning teeth and removing plaque from deep between teeth. 【Replacement Indicator】 The blue indicator bristles fade halfway to signal when it's time to replace the brush head. Dentists recommend replacing them every 3 months. 【Economical Set of 4】 This value pack includes 4 brush heads in three colors: white, blue, and green, suitable for the whole family. - Model Number: P-HX-6064 - Quantity: Pack of 4 - Colors: White, Blue, Green - Features: Uses US Dupont Tynex nylon bristles - Recommended Replacement Frequency: Every 3 months - Indicator Bristles: Blue indicator bristles Thank you for viewing.