Protect your Nuna® Sena Aire™ Mattress with the Nuna Sena Waterproof Mattress Cover with Built in Nuna Organic Sheet. The elastic band ensures a perfect fit around your Nuna mattress, while the waterproof inner prevents the Nuna mattress against any little accidents. TheNuna Organic Cotton cover top is GOTS certified organic, to provide a safe and comfortable environment for your precious baby to sleep.