The Tahoma Field Knife, a large fixed blade designed by Andy Tran of InnerBark Outdoors and produced by TOPS Knives, is one of the finest large survival knives on the market. It comes from TOPS with functional sheath but there is always room for improvement.
InnerBark Outdoors worked with Red Feather Gear to develop is a kydex dangler sheath for the Tahoma Field Knife. The sheath has a welt to add rigidity which is nice for such a heavy knife. It also features a closed dangler loop that can not be accidentally opened and a well formed thumb ramp to aid in removing the knife from the sheath.
Check out the Tahoma Field Knife Kydex Sheath at InnerBark Outdoors. The price is quite reasonable considering the size of the sheath.