Razor 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. In 1901, the American inventor King Camp Gillette, with the assistance of William Nickerson, patented a new variation of safety razor with disposable blades. Gillette realized that a profit could be made by selling an inexpensive razor with disposable blades. This has been called the razor and blades business model, and has become a very common practice for a wide variety of products. Many other brands of safety razors have come and gone.
Kawasaki triple motorcycle collectors was nostalgic for H1 Mach IIIs along with other bikes of the era, Honda CBs and CLs, Yamaha RD350s and Suzuki Hustlers. In 1971, the S2 350 was introduced, and in 1972 its smaller brother, the S1 250 became available. The H2 750 was introduced in 1972, the culmination of Kawasaki's two-stroke project. Kawasaki said of the bike, "It's so quick it demands the razor-sharp reactions of an experienced rider." Its engine displacement of produced at 6,800 rpm. The engine was entirely new and not a bored-out 500. With larger displacement as well as less aggressive porting and