Actually would have to write this review of our little mouse. She sleeps at noon or so away it there. But I have a feeling she's sleeping since quieter and longer. We have a RB from Hauck. There is indeed a mattress it, but turn around at every rustling there and you will inevitably awake. In addition, it is not very soft. The RB-mattress H5008-008 of Herlag is there already different. It is lightweight, washable (cover removable), can be folded up in no time and stowed in the protective sheath. Super for the journey. Super quality of Kettler. Just buy it !!!