Oral-B's improved CrossAction toothbrush heads are developed with CleanMaximiser technology that turns green bristles yellow for optimal brush head performance and the best clean. The unique bristles reach deep between teeth to remove plaque and leave your whole mouth cleaner than with a regular manual toothbrush. Compatible with all Oral-B handles except Pulsonic iO. Oral-B Cross Action White Clean Maximiser Replacement Toothbrush Heads 4x