The shaker of Ironmaxx dissolve the powder in water / milk perfectly and leaves no residue. The result is neither a strange taste or smell through the PET. It's perfect for traveling and keeps in treated with respect they also very long -> tip for the price. It is only necessary to ensure that just touches the cover and missile?. Otherwise, the tightness is not given, as there is no rubber seal but only screw the shaker seals. Thus it is, however, also easily fit dishwashers. For this price a super Shaker!