VEXpro 2014 Drive in a Day Chassis Kit and Accessories - VEXpro 217-3654, These cross rails have been designed for use with the VEXpro 2014 FIRST ® Robotics Competition Drive in a Day Chassis, 70-3321. The 2014 Drive in a Day is a configurable chassis system that produces lightweight, affordable, and robust sheet metal drive-trains. With a 0.5in. pitch and a wide variety of mounting holes for motors, gearboxes, and bearings, teams can use the 2014 Drive in a Day to build the drive-train that\'s right for them. VEXpro 217-3654 Cross Rail (2-pack)