The Naomi Home Kids Low Study Loft Bed is a stylish multifunctional piece for a child's bedroom. The strong build assures that this bed will last while keeping your child snug at night. Equipped with a pull out desk and book shelf, early morning or late night study could not be made any easier. The Naomi Home Low Study Loft Bed has all the essentials and more to ensure that no child wakes up on the wrong side of the bed. Can use twin mattresses 75 x 38. Mattress that is 8" high should work fine. These chairs do not come with cup holders. We do not sell cupholder separately. The height of the pull out desk is 25.8 inches. The railings around the mattress base are 12 inches high. Any mattress that fits inside that should be safe to use. The drawers are about 6.00" deep. The bed can be set up either way with the ladder and bookcase at either end while assembling, kindly refer assembly manual. Drawers inside dimensions 26.5"Wx 13"Dx 6"H. Box spring is not required.