The Darwin Universal Razor is a wedge blade design that can be honed and stropped within it's own case. It came with two blades to switch out allowing the blades to rest between shaves. The hone and strop is to maintain the blade and not fully restore it, but only to refresh the edge. There's where the similarities basically stop. The Darwin was marketed as the "Aristocrat of the Bathroom" and some would say was a step above the Rolls Razor in design and functionality.

Now the differences. The Darwin Universal is a step beyond being a straight razor on a stick and the blade holder is far more recognizable as a true safety razor with it's open comb features. The blade slides into the older and a spring mechanism holds the blade loosely in place until the handle is screwed into the underside of the blade holder locking it firmly in place. The bottom of the handle unscrews revealing a small screwdriver with which the blade gap of the blade can be adjusted before the handle is firmly screwed in place. There are even notches to show the adjustment level, although I found them not as useful as just eyeballing the blade gap.

The handle also can be screwed into either side of the blade allowing for the blade to be moved and positioned either in the blade holder, the stropping mechanism or the spare blade holder without your fingers being exposed the the very sharp exposed blade edge.

The Darwin Universal Razor's inventor was a pioneer in the production of cobalt steel and early double edge razor blades so naturally the blades are made from cobalt steel. The handle I believe is also cobalt steel. The case is beautifully chromed and sturdy. The mechanism works very well. The Rolls Razor utilized a stone hone and leather or cork strop. The hone and strop of the Darwin is leather with one side being "coarse" and the other "fine" with the sharpening characteristics of the hone/strop coming from the application of stropping pastes or compounds.