Made of high-quality materials, so the shaver head is durable, efficient and easy to use. Compatible with Braun21B, Braun 3 series, such as 301S, 310S, 320S, 330S, 340S, 350CC, 360CC, 360, 370, 380, 5774, 5775 and more. Shaver head should be replaced every eighteen months. For optimum performance, please clean regularly. The replacement head provides your shaver back to 100% performance and a closer shave, making shaving faster, smoother, and more thorough.