Enjoy the strong support and convenience of the new Walter 4 Inch Smart Box Spring by Zinus, offering the look and functionality of a traditional box spring, but made from steel for longer-lasting durability. Wood slats provide strong, comfortable support. Compact packaging allows for tight interior spaces such as stairs and hallways. Easy assembly with all the needed tools included. Worry free 5 year limited warranty. Another comfort innovation from Zinus. Frame and Mattress sold separately.