Kings Brand Furniture Black Metal Twin Size Day Bed (Daybed) Frame with Pop Up Trundle Kings Brand Furniture Black Metal Twin Size Day Bed (Daybed) Frame with Pop Up Trundle. Accepts twin size mattresses, Includes platform with metal slats. No need for a box spring or separate bed frame. Dimensions: Daybed:78"W x 41"D x 42"H. Trundle: Open Dimensions: 72"L x 39"W x 17"H. Closed Dimensions: 72"L x 39"W x 4"H.