Lost Mountain Iron Works (LMIW) makes some of the most feature rich knife sheaths that you will have see. It really isn’t fair to call them sheaths because that doesn’t begin to scratch the surface of their functionality. They are really more like packs that also happen to hold a knife.
They have three models that serve various sizes of knives. The Works Pack is essentially an organizer style pack that accepts a kydex knife sheath. It allows to build a compact, knife-based survival kit. The interior features mesh pockets that let you stash your gear but still be able to see it. The Works Pack also features an external pocket. There are also elastic loops on the exterior for lashing additional gear. A tool hanger allows you to attach a small tool like a fire steel. The entire pouch can be attached to a larger pack, chest rig, or any thing else with MOLLE webbing. This pouch might be the ultimate E&E kit.
LMIW also makes two longer sheaths for larger fixed blades – the Footlong and the J. Holmes. These sheath feature a kydex insert for holding the knife and two large external pouches. The pouches are sized to hold Altoid sized tins or several small items. They are also MOLLE compatible.