Pack of 4 toothbrush headsNo.1 dentist recommended brand worldwide. The round petal shape is designed with dentists. It has soft, ultrathin bristles that are gentle on gums, combined with regular bristles that are tough on plaque. Sensi Ultrathin removes up to 100% more plaque and reduces gum inflammation by 100% compared to a manual toothbrush. Ultrathin bristles make Sensi Ultrathin ideal for everyone with a sensitive mouth and everyone who is looking for just a great gentle clean. Compatible with Oral-B Genius 8000, 9000. Oral-B Smart 4000, 4900, 5000, 6000, 6500, 7000. Oral-B PRO 600, 650, 1000, 2000, 2500, 3000. All Oral-B Vitality and Vitality Plus Variants.