These are the optional Team Integy Evolution-5 Rear Upper Arms for use on the Traxxas E-Revo and Revo 3.3 Vehicles. FEATURES: Aluminum construction Anodized blue in color INCLUDES: Two Evo-5 Rear Upper Arms Two 3x9.5mm Cap Head Screws REQUIRES: Installation on the vehicle SPECS: Length: 125mm (4.9") Width: 75mm (3") Height: 14mm (0.55") COMMENTS: Also available in Silver (INTC7978) IntegyPart INTT3261BLUE