Double Edge razor: Introduced at the beginning of the 20th Century, the Open Comb was de rigueur for shaving around and about the ample moustaches and side burns popular during that period. The comb rakes or channels a mass of hair between its teeth for a smooth cut. Today, this style is normally preferred only by shavers who have extremely tough, thick, fast-growing whiskers. The shaver's experience with an Open Comb may be less gentle than with a Straight Edge, depending upon skin sensitivity.
(a.k.a. Safety Bar) Double Edge razor: The Straight Edge, considered an advancement in the design of the double edge razor, is by far the most popular as gentlemen are less likely to be sporting the ample side burns, moustaches, and beards of their great grandfathers. The safety bar provides additional protection against nicks by keeping the skin taut between bar and blade providing a smooth, flat surface for cutting. Recommended for shavers not experienced with a double edge razor.
Slant Bar Double Edge razor: The Slant Bar has a uniquely designed slanted blade-guard which causes the blade to slice through heavy beards rather than pull through them (just as a snow-plow blade is angled to easily work through a pile of snow). The Slant Bar is handled exactly as any other double edge razor, no special manipulation is required. This razor has a reputation as a very aggressive shaver and is recommended mainly for the experienced safety razor user with a particularly thick or coarse beard. Not a good choice for the beginner.