Nerf was introduced in 1970 by Hasbro as a ball that was safe to use indoors, with really great marketing slogans like: "Throw it indoors; you can't damage lamps or break windows. You can't hurt babies or old people." Well, it’s still true! Sometimes you just need a ball—so low tech, so thoroughly enjoyable. Don’t overlook it! This foam ball is about 4” across.