The Olympic Torch is based on traditional scrolls and uses a traditional Chinese design known as "Lucky Cloud". It is made from aluminum. It is 72 centimetres high and weighs 985 grams. The torch is designed to remain lit in 65 kilometre per hour (37 mile per hour) winds, and in rain of up to 50 millimetres (2 inches) per hour. An ignition key is used to ignite and extinguish the flame. The torch is fueled by cans of propane. Each can will light the torch for 15 minutes. It is designed by a team from Lenovo Group. The Torch is designed in reference to the traditional Chinese concept of the 5 elements that make up the entire universe.