✔Premium quality: Equipped with a cutting edge dual blade system with lift and cut technology. Stainless steel blades for a comfortable close shave. Suitable for meticulous grooming and ensures safe use. The flexible pivoting head adapts perfectly to any surface, always delivering excellent performance. ✔Compatible models:Blade model 21B, compatible with all electric shavers series 3 shavers 301S, 310S, 320S, 330S, 340S, 360S, 3000S, 3010S, 3020S, 3030S, 3040S, 350CC, 370CC, 3050CC, Cruzer 6 and so on. ✔Professional shaving head:21B shaving head with floating lock, precision tooth comb technology and bionic mesh design perfectly fits your skin and grips the male hairs firmly, thus removing them easily without damaging the top layer of skin. Bring you a more comfortable and efficient shaving experience! ✔Long lasting: The lifespan of the foil and cutter replacement heads compatible with the s3 varies depending on your daily use. For optimal performance, it is generally recommended to replace them every 9-12 months. This ensures that you always enjoy the best haircutting experience. Replacement foil heads are easy to install and remove. Clean the shaver before installing the shaver foil. ✔Waterproof shaving head:Made of high-quality waterproof material, it works effortlessly in wet conditions, providing an efficient and stable epilation experience for the razor, just like the original razor head.