Panasonic electric shavers are packed with smart, innovative, features that deliver a remarkably close and comfortable shave. All Panasonic men’s shavers are fully waterproof for wet/dry cordless operation. Use the shaver dry for a quick, smooth shave—perfect for when you’re in a hurry in the morning or want a quick touch up before going out in the evening—or a luxurious, pampering wet shave with foam or gel. Because they"re waterproof, you can enjoy the freedom of taking your shaver in the shower and the convenience of rinsing it clean under running water. The ES-RF31-S has a 4-blade cutting system. More foils means better coverage and reduced shaving time. And since our foils feature varying configurations, they work together to capture hairs of different thickness or growing patterns. So you’ll get a close, comfortable shave and finish more quickly. The ES-RF31-S also has an ultra-thin vibrating outer foil which is a perforated, curved metal casing that covers the blades. Whiskers are cut when they enter the holes in the foil.The foil on a Panasonic shaver is incredibly thin – only 41 micrometers on select models – so the blades get closer while the foil protects your skin. Further, our shaver motors charge the foil with subtle yet rapid vibrations which gently lift the hair follicles for a closer cut while helping the shaver to glide even more smoothly across the skin. Panasonic shavers feature ultra-sharp Nanotech™ blades—a name derived from a special nano-polishing technique used to shape the blade’s leading edge. Nanotech™ blades are honed at an acute 30º angle enabling whiskers to be cut more cleanly at the root. The Multi-fit arc foil allows the shaver to glide uniformly over the chin and along the jaw line. The arc foil, also allows the shaver head to move in a circular motion—ideal for those accustomed to a rotary shaver.