This adorable little acorn has a hidden space inside that can hold a thimble.  The top is walnut and the actual nut part is maple wood.  It is waxed, not varnished.  It comes in 3 sizes.  The outside is essentially the same but the inside wall is thicker (for a smaller inside space) or thinner (for a larger inside space).   If you are ordering online, tell me which thimble you want to fit into the nut and I'll find a size for your thimble.