<R4>
Robots must fit within an 18” x 18” x 18” volume. Compliance with this rule must be checked using the official VEX Robotics On-Field Robot Expansion Sizing Tool. Any restraints used to maintain starting size (i.e., zip ties, rubber bands, etc.) must remain attached to the Robot for the duration of the Match, per <G6>. For the purposes of this rule, it can be assumed that Robots will be inspected and begin each Match on a flat standard foam field tile. The official sizing tool is intentionally manufactured with a slightly oversized tolerance. Therefore, any contact with the sizing tool (i.e., a “paper test”) while being measured should be considered a clear indication that a Robot is outside of the permitted size. This tolerance also provides a slight “leeway” for minor protrusions, such as screw heads or zip ties. Other tools, such as custom sizing boxes or the legacy non-expanding VEX Sizing Tool (276-2086), may be used for informal checks. However, in the event of a conflict or “close call,” a check with the official On-Field Robot Expansion Sizing Tool takes precedence.