In a first embodiment, a pre-formed pouch is provided that includes a plurality of walls joined in order to define an aperture. An assembly may be inserted into the aperture, which may then be sealed. Further, the pre-formed pouch may be fitted to the shape or dimensions of the assembly that will be inserted. In a second embodiment, an assembly may be covered in a plurality of layers of material, such as first layer of plastic, a layer of metal, and then a second layer of plastic. Each of the coverings may be formed by dipping the assembly in plastic or metal (or other material), molding layers around the assembly, coating the assembly in the layers, vapor depositing plastic or metal (or other material) onto the assembly, and/or a combination of these operations.