The "original kitchen aid" was developed and patented in the 1930s by the long-established blacksmith shop of Zwilling J.A. Henckels.
Despite its unusual blade thickness of 3.5 mm and sheer mass, the rust-proof, forged, ice-tempered special steel, the shears have a silken gait that literally "sings" as it cuts in finely distinguished tones that even the unpractised ear can hear. Which distinguishes it utterly from the rickety knock-offs from the Far East. The blades are finely serrated and the scissors gait is adjustable.