28" x 76" x 3" Twin Mattress - Twin Size Fold Up Bunk Beds - This bed folds up against the wall during transport. Beds will support 1,000 lbs. maximum. Mattress is included. Folds up against wall for maximum storage space. Includes ladder and saftey rails as required by the Consumer Product Safety Commission. Totally removable with easy one hand operation. Designed with springs to support mattress versus plywood for better comfort. Ladder can be rotated from right to left (universal position). Adult can sit on bottom bunk with plenty of head clearance.