This yard sign is made up of corrugated rainbow letters. Included metal stakes make it easy to plant outside. Simply insert metal stakes about 2 inches apart into the bottom of the sign and push rods into the ground. Place them on your front lawn to let neighbors know what all the fuss is about or to greet the birthday celebrant when they arrive to the party. Rainbow Happy Birthday Yard Sign product details: 4 letter pieces 12 1-4in tall 8 metal stakes Arrives flat Simple assembly required.