Old two handle cheese cutter for cutting a large wheel of cheese. This came out of the estate of a Swiss cheese maker, here in 'cheese country' Green County, Wisconsin.
It measures 12 1/2" across the blade, 21 1/2" long overall. It's not marked that we could see, but probably French or German?
This knife has professional chef's quality full tang riveted handles, but it does have some rust spotting to the blade.