on dry skin only. Many recent electric razors have been designed to allow for wet/dry use, which also allows them to be cleaned using running water or an included cleaning machine, reducing cleaning effort. Some patience is necessary when starting to use a razor of this type, as the skin usually takes some time to adjust to the way that the electric razor lifts and cuts the hairs. Moisturizers designed specifically for electric shaving are available. Battery-powered electric razors In the late 1940s, the first electric razors that were battery-powered entered the market. In 1960, Remington introduced the first rechargeable battery-powered electric razor. Battery-operated electric razors have been available using rechargeable batteries sealed inside the razor's case, previously nickel cadmium or, more recently, nickel metal hydride. Some modern shavers use Lithium-ion batteries (which do not suffer from memory effect). Sealed battery shavers either have built-in or external charging devices. Some shavers may be designed to plug directly into a wall outlet with a swing-out or pop-up plug, or have a detachable AC cord. Other shavers have recharging base units that plug into an AC outlet and provide DC power at the base contacts (eliminating the need for the AC-to-DC converter to be inside the razor, reducing the risk of electric shock). In order to prevent any risk of electric shock, shavers designed for wet use usually do not allow corded use and will not turn on until the charging adapter cord is disconnected or the shaver is removed from the charging base. In 2017, Xiaomi released an electric shaver with USB-C charging. Razor vs. trimmer An electric razor and an electric trimmer are essentially the same devices by build. But the major difference between both comes in terms of their usage and the blades that they come with. Electric razors are made specifically for providing a clean shave. It has lesser battery power but more aggression towards clipping hair. Electric Trimmers, on the other hand, are not meant for clean shaves. They come with special combs fixed onto them that aid in proper grooming and trimming of the beard stubs to desired shapes and sizes. General Some models, generally marketed as "travel razors" (or "travel shavers"), use removable rechargeable or disposable batteries, usually size AA or AAA. This offers the option of purchasing batteries while traveling instead of carrying a charging device. Water-resistance and wet/dry electric shavers Many modern electric