There isn’t a knife that fits this sheath... - Spec Ops Combat Master Fixed Blade Knife Sheath

There isn’t a knife that fits this Sheath, which is a shame as it’s a well-made but apparently useless item. OpticsPlanet does not sell a knife that fits this sheath; I purchased it for a knife I ordered from them, which did not fit. I have contacted OpticsPlanet and have been promised a list of suitable knives but have yet to receive said list. I will be returning the sheath.