ARRMA ARA340183 HD Servo Saver Spring Set Suit 8S Outcast and Kraton / This Heavy Duty Servo Saver Spring Set provides ideal parts for your ARRMA vehicle. Key Features: Constructed from strong and durable spring steel for long-lasting performance, precision manufactured for consistent operation in extreme conditions, springs are 13% stiffer than #ARA340168. What’s In The Box? 1 x Servo Saver Inner Spring, 1 x Servo Saver Outer Spring, 1 x Steel Washer 17 x 27 x 1mm.