REAR UPPER ARMS REVO BLUE Optional Golden Horizons Blue Aluminum Rear Upper Arms for the Traxxas Revo. FEATURES: Aluminum Construction, Blue in Color, Very Durable. INCLUDES: (2) Rear Upper Arms REQUIRES: Installation onto the Revo SPECS: Length: 4-15/16 (125mm), Width: 2-3/4" (70mm), Thickness: .316" (8mm)