Replacement Pack Er-6Ct02 Contains 4X Extra-Fine Brush. It Is Recommended To Exchange Toothbrushes Regularly. If You Own The Electric Toothbrush Head Attachment (Er-Ctb1), The Replacement Pack Is The Perfect Fit Customise Your Experience: The Multishape Modular Personal Care System Is Compatible With All Multishape Accessories, Including Beard/Hair Clipper, Beard/Hair/Body Trimmer, 3-Blade Shaver, Electric Toothbrush And Nose/Ear/Facial Trimmer. Customise Your Experience With A Wide Selection Of Interchangeable Heads Simplicity and Sustainability: The Easy-To-Use Modular System Is Ideal For Travelling And Keeping Your Bathroom Clutter-Free. Changing Your Grooming Style By Only Adding Attachments Makes It The Perfect Sustainable Gift Sonic Vibration Technology For Deep Cleaning: This Electric Toothbrush Features Unique Sonic Vibrations To Help Remove Plaque From Hard To Reach Periodontal Pockets, Delivering A Deep, Gentle Clean EXTRA-FINE TRIPLE-EDGED BRISTLES: Extra-fine bristles target narrow periodontal pockets, while the triple-edged shape provides an overall thorough clean.