A Can Opener (or tin opener) is a device used to open metal cans. Although preservation of food using tin cans had been practiced since at least 1772 in the Netherlands, the first can openers were patented only in 1855 in England and in 1858 in the United States. Those openers were basically variations of a knife, and the 1855 design continues to be produced. The first opener employing the now familiar sharp rotating wheel, which runs around the can's rim cutting the lid, was invented in 1870 but was difficult to operate. A breakthrough came in 1925 when a second, serrated wheel was added to hold the cutting wheel on the rim of the can. This easy to use design has become one of the most popular can opener models.
Around the time of World War II, several can openers were developed for military use, such as the American P-38 and P-51. These featured a robust and simple design where a folding cutting blade and absence of a handle significantly reduced the opener size. Electric can openers were introduced in the late 1950s and met with success. The development of new can opener types continues with the recent addition of a side-cutting model.