Your perfect shave - with our most innovative shaving technology Series 7 is the most technologically advanced shaver from Braun. Its revolutionary sonic technology automatically adjusts its power to the density of your beard and delivers an exceptional 10,000 micro vibrations with every stroke - for the ultimate thorough and comfortable shave. Furthermore, the Series 7 combines uncompromising German engineering and manufacture with world-famous Braun design. Features: Powerful rechargeable Li-Ion battery with no memory effect All Series 7 shavers are rechargeable, and work both cordless and corded. BraunËœs Series 7 shavers are powered by a 3.6V Li-Ion battery with no memory effect.