So I have these two for sale , both have been used but are in good condition. The black one is only 300 ml in capacity and i found needed emptying approx every 10 days but is baffled, one inlet and one outlet. The silver one has two inlets (one above the other) and one outlet and is baffled vertically. Approx 600-700 ml's capacity. Both have 19mm connections. Only really looking for postage costs.