The 2009 Times Square Ball used 2,688 illuminated triangular crystal panels.
The 2009 ball introduced a major redesign for the centennial of the ball-drop tradition. Waterford Crystal created a geodesic sphere covered with 2,688 crystal triangles, and Philips supplied LED lighting capable of producing millions of color combinations. The design was larger and more technologically advanced than earlier versions.
The panels were arranged in different sizes and patterns across the sphere, allowing the ball to produce changing visual effects during the descent. The ball measured 12 feet in diameter and weighed nearly six tons, making it dramatically different from the small iron-and-wood ball used in 1907.
The number 2,688 describes the crystal triangles on that version of the ball, not every ball ever used in Times Square. Later designs changed the panel count and visual arrangement while retaining the basic annual descent from One Times Square.