★This bed is "customer assembled furniture"★ For "customer-assembled furniture," we ask that customers unpack, assemble, and install the product themselves. Mattress, single, for stretchy loft beds, a Stretchable mat (sold separately) This mat is exclusively for the stretchy Scelta bed and the stretchy Scelta-high loft bed, and can be adjusted to fit any bed size from 150cm to 210cm. The length can be easily adjusted with the Velcro.