Hi, Digitec has asked for help for you. The filter consists of a very fine metal mesh that is moulded into a plastic frame. The filter can be pulled out of the plastic holder. As described, the housing is double-walled and made entirely of stainless steel. The volume specification for the double-walled version is 1.3L (the single-walled version has 1.6L). The filling quantity is inside, but you can feel the filling in no time. I can recommend this product with a clear conscience.