for high traction tracks 1-piece design CNC-machined graphite Machined from 2.0mm high-grade graphite, the optional 1-piece long top deck is recommended for high-traction carpet and astro conditions. The top deck reinforces the chassis assembly by connecting the front diff bulkhead with the central drive system, and provides a location for the body mount. The top deck captures the central drivetrain bearings and holds them in place in their supporting bulkheads.