In 18 months, your Braun shaver cuts an average of 6,000,000 hairs This causes the cutting parts to gradually wear down, which can result in a less comfortable shave. Therefore, Braun recommends that you replace the cutting blade and the scissor head every 18 months to keep the shaver in good condition. Take care of your shaver, and it will take care of you. TOP PERFORMANCE: Braun recommends replacing the shaving head every 18 months for continued excellent results CUSTOM SHAVING: with pressure-sensitive blades that automatically retract to protect your skin FAST AND EFFICIENT: with the 3 flexible blades of the shaving head EASY CHANGE: it is easy to change to a new shaving head - just click QUALITY CRAFTSMANSHIP: 100% made in Germany and compatible with all Series 3 shavers