Designed for disassembling fish, this thin flexible knife with a razor edge is excellent for that task, but pretty useless for anything else. The Filleting Knife must be accompanied by a stone because its delicate edge needs to be resharpened often, usually before the next fish.
The photo specimen, with a 6-1/8 inch blade (about the shortest you would want) is a very popular knife made in Finland by J. Marttiini and comes with a leather belt scabbard. This knife has been made for about 80 years and is available at prices from US $18.00 to $25.00.
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