6-Pack Premium Standard brush heads are compatible with: Philips Sonicare Advance- CleanCare- Elite- Essence- and Xtreme power toothbrushes. Premium Standard Toothbrush Heads include caps for hygienic storage and travel. Brush heads screw on for easy replacement and cleaning. Premium standard sonic toothbrush heads are proven to reduce gingivitis up to 100% better than a manual toothbrush. Premium Standard toothbrush heads are made to the highest health and safety standard.Usually three months is the estimated time for a change of the brush head as per dental professionals recommendations.