Safety razor entitled "Fuck Everything, We're Doing Five Blades" predicted the release of five-blade cartridges, two years before their commercial introduction. South Korean manufacturer Dorco released their own six-blade cartridge in 2012, and later released a seven-blade cartridge. Gillette has also produced powered variants of the Mach3 (M3Power, M3Power Nitro) and Fusion (Fusion Power and Fusion Power Phantom) razors. These razors accept a single AAA battery which is used to produce vibration in the razor; this action was purported to raise hair up and away from the skin prior to being cut. These claims were ruled in an American court as "unsubstantiated
Straight razor more feedback on the resistance the blade meets while cutting the hair, which is an indicator of blade sharpness. Hollow-ground blades are preferred by most barbers and some high-end razor manufacturers limit their production exclusively to hollow ground razors. The third and final category refers to blade width. The width of the blade is defined as the distance between the back of the blade and the cutting edge. It is expressed in units of eighth of an inch. The sizes vary from up to , rarely . A wider blade can carry more lather, much like a scoop, during multiple