Deep Clean Rechargeable Electric Powered Toothbrush, Black with iO Series 3 Limited, 2 Brush Heads and Travel CaseProtect Your Gums with iO Pressure Sensor: This is only brush with a built in sensor that alerts you if you're applying too much or too little pressure, ensuring you clean effectively and safely without harming your gums. Maximize Your Clean: The iO LightRing Timer ensures you're brushing for the dentist recommended 2 minutes, and it includes a refill change alert to remind you when its time to replace your brush head for optimal performance.