The coffee grinder, made of metal, has two rotating wheels on both sides attached to an iron bar in the middle to fix the wheel firmly and to create stronger grinding power, and smoother coffee, above is a large funnel containing roasted coffee beans to grind into a coffee powder with a maximum fineness of 1.7 micrometers. In small cafés in Germany today, there are still similar manual grinders with many capacities depending on the doer’s hand strength. Until the 1930s, the manual grinders seemed to be no more but instead, those were modern coffee production technologies, in which the CARAVEL grinder was not an exception.