Description Powerball Navi-Ball Rolling Stone – 20-9809 White zirconia ceramic “Powerball” used in Bally’s Twilight Zone pinball machine. This is also the “Navi-Ball” used in Stern’s Avatar LE pinball machine, and the “Rolling Stone” used in Stern’s Rolling Stones LE pinball machine. New production bright white pearlescent color (as original). Conforms to the original size and weight specifications: size – 1-1/16″ diameter, weight – 65 grams. References ; Bally Williams – 20-9809 Stern – 260-5012-00
