The Pro-Line Builder’s Series: Metric 12.3" Rock Crawler Body was designed specifically for those who enjoy fully customizing their rigs. Just like a full-size project truck that you build exactly how you want, the Builder’s Series: Metric Body allows for custom grills, lights, engine detail and nearly any other scale detail you can imagine with the help of 3D printing technology. Pro-Line has joined forces with leading custom 3D Scale Parts company Knight Customs, so you have a ton of realistic scale option parts already available for your Metric build!