View Larger Trundle/Storage Drawer Collection: Bunkhouse Item #: 8830-9500 75W x 41D x 13H On Casters. Use with the 8830 Twin & Full Panel Beds, Bunk Beds, and Mid Loft as Standard Height Bed. Cannot be used w/Queen Panel Bed or Mid Loft Bed w/Extenders in Place. Takes a standard twin mattress (max size: 75x39x8) for use as an extra bed or 2 removable dividers (included) allow for organized underbed storage option. Requires Bed Rails. Rails must be in high position.