Texture Black Metal Twin Size Day Bed (Daybed) Frame With Rails & Trundle Texture Black Metal Twin Size Day Bed (Daybed) Frame With Rails & Trundle. The day bed is one of our newest daybed introductions and features a design and finish scheme which offers style and sophistication. The day bed will work well in any room setting. Accepts twin size mattresses, Includes platform with 7 metal slats, (No need for a box spring or separate bed frame.). Dimension: Daybed:79.375" x 42.25" x 38.5"H, Trundle: 75.5 " L 39". Simple assembly required. The mattresses are not included it could be purchased separately.