If you use an inner/outer belt set up, I have good news. Snake Eater Tactical has made the excellent inner belt that they use in their SET War Belt available for purchase separately.
I have been using the SET War Belt over the winter and have really come to like the inner belt. It is made from a thin layer Hypalon with loop Velcro sewn to it instead of a piece of webbing with bound edges like most inner belts. The Hypalon Liner Belt is extremely thin and flexible which means it is extremely comfortable under a weight bearing belt.
There is no buckle. The belt overlaps onto itself and secures with Velcro. This is not unlike most inner belts. However, the Hypalon Liner Belt has some extra insurance to prevent it from working loose over time like typical inner belts. It has a fold over section that wraps all the way around the belt to really lock it down.
The Hypalon Liner Belt may not be the sexiest part of the SET War Belt but it is one of the best. It is great to see this offered separately. Now if I could just talk them into selling the great pad that they use in the SET War Belt separately, the wold would be a better place.