The blade and the replacement cutting part are compatible with all Braun Series X beard trimmers and electric hybrid shavers. It features a blade with four cutting elements - two side trimmers and two middle shaving surfaces. The specialized 4D blade technology ensures a simple and comfortable shave that is also gentle on the skin. The blade is waterproof and made of 100% stainless steel. It is designed for long-lasting use and can last up to six months (based on two full shaves per week; actual results may vary).