Wikipedia
Srbosjek (literally "Serb cutter" in Croatian and Serbian, often referred to as "cutthroat") is the colloquial Serbo-Croatian term for a type of agricultural knife manufactured for wheat sheaf cutting, because of its use in killing prisoners in Croatian concentration camps in World War II.
The knife gained notoriety in the former Yugoslavian countries because it was probably used by the Croatian Ustaše during World War II for the killing of prisoners in the concentration camps of the Nazi-puppet Independent State of Croatia, most notably the Jasenovac concentration camp. The victims were Serbs, Jews, and Roma, imprisoned on 'ethnic' grounds, and significant numbers of Croats, imprisoned on the grounds that they were Partisan resistance members, or on the suspicion of taking part in anti-fascist activities.David M. Kennedy, Margaret E. Wagner, Linda Barrett Osborne, Susan Reyburn, The Library of Congress World War II Companion (Simon and Schuster, 2007), pages 640, 646-47, page 683:
At Jasenovac, a series of camps in Croatia, the ultranationalist, right-wing Ustasha murdered Serbs, Jews, Gypsies, Muslims, and political opponents not by gassing, but with hand tools or the infamous graviso or srbosjek (literally, "Serb cutter") - a long, curved knife attached to a partial glove and designed for rapid, easy killing.
The upper part of the knife was made of leather, as a sort of a glove, designed to be worn with the thumb going through the hole, so that only the blade protruded from the hand. It was a curved, 12 cm long knife with the edge on its concave side. The knife was fastened to a bowed oval copper plate, while the plate was fastened to a thick leather bangle. Its agricultural purpose was to make it easier for the field workers to cut wheat sheaves open before threshing them. The knife was fixed on the glove plate in order to prevent injuries and to prevent taking care of a separate knife in order to improve the work speed.
Such a type of wheat sheaf knife was manufactured prior to and during World War II by German factory Gebrüder Gräfrath from Solingen-Widderit under the trademark "Gräwiso". Gebrüder Gräfrath was taken over in 1961 by Hubertus Solingen.