All of our mattresses are compatible with a NEW slatted bedstead; you must however ensure that the slats on the bedstead are no more than 3.0” (7.5cm) apart and that there is a central support rail on ‘Double’ sizes (135 x 190cm, approx. 4’6 x 6’3) or over. Generally slatted bedsteads will give a mattress a firmer feel, it is therefore important when you are trying Hypnos mattresses to check what style base the mattress is sitting on, bearing in mind that a mattress displayed on a sprung divan base will feel firmer when it is placed onto solid slats.