Braun 53B head and blade for Series 5/6. Over the course of 18 months, the Braun shaving mechanism will cut an average of 6 million hairs, shaving an area equivalent to the size of a football field. During this process, the cutting parts will gradually wear down. The precision and comfort of shaving may decrease. It is recommended to replace the head and blade of the shaver every 18 months to ensure maximum performance. A perfect shave every day.