Turn your Oeuf River Twin Bed into the ultimate big-kid bed, with the addition of this fun hide-away trundle bed! It tucks away neatly when not in use, and fits a standard-sized twin mattress inside so your sleepover guests can rest soundly. (Mattress sold separately.) It even doubles as an under-the-bed storage unit when you remove the mattress, so you can store blankets, clothes, and more inside.