The term safety razor was first used in 1880 and described a basic razor with a handle attached to a head where a removable blade may be placed. The edge was then protected by a comb patterned on the head to protect the skin. In the more modern-day produced safety razors, the comb is now more commonly replaced by a safety bar. There are two types of safety razors, the single edged and the double-edged. The single-edged razor is essentially a long segment of a straight razor. The double-edged safety razor is a razor with a slant bar that can be used on both sides, with two open edges. The blade on the double-edged safety razor is slightly curved to allow for a smoother and cleaner shave.