Group, Saudi Arabia's largest construction company. The façade was constructed by Premiere Composite Technologies, and the clock by German tower clock manufacturer PERROT GmbH & Co. KG Turmuhren und Läuteanlagen. According to the Saudi Ministry of Religious Endowments, the project cost US$15 billion. Clock The project uses clock faces for each side of the main hotel tower. The total height of the clock is 57 m (187 ft), just below the media displays under the clock faces. At 43 m × 43 m (141 ft × 141 ft), these are the largest in the world. The roof of the clock is 450 m (1,480 ft) above the ground, making it the world's most elevated architectural clock. A spire has been added on top of the clock giving it a total height of 601 m (1,972 ft). Behind the clock faces, there is an astronomy exhibition. In the spire base and the iron-covered floors (The Jewel) there is a scientific center that is used to sight the moon at the beginning of the Islamic months, and to operate an atomic clock that controls the tower clock faces. List of component towers Features The building is topped by a four-faced clock, visible from away. The clock is the highest in the world at over above the ground, surpassing the Allen-Bradley clock tower in Milwaukee. The clock faces are the largest in the world, surpassing the Cevahir Mall clock in Istanbul. Each of the clock's four faces measures 43 m (141 ft) in diameter and are illuminated by 2 million LED lights, with four oriented edges, just above the clock alongside huge Arabic script reading: "God is [the] greatest" on the north and south faces and on the west and east "There is no god but Allah. Muhammad is the messenger of God.". Four golden domes on pillars on all the corners are also present. The same as the Saudi Flag, fitted at the top of the clock, flash to signal Islam's five-time daily prayers. On special occasions such as new year, 21,000 green and white xenon bulbs and LED lamps during the call to the five prayers times of the day. On special occasions, 40 beacons lights allow innumerable variations of splendid lighting effects. In. addition, the world’s strongest four show lasers throw their rays 30 kilometers into the sky. The clock's four faces are covered with 98 million pieces of glass