These are "Factory Seconds" in that we are not 100% confident in the gluing quality inside on the bead of the tire. These are also our mis-timed I-Beam tires with the wide center bar. Perfect for someone willing to run them once and re-glue any spots that may pull away from the wheel. They could be 100% fine, but we don't know so that why they are being sold as a "Factory Second".
The I-BEAM is designed for traditional tracks with a little bit of loose dirt. The larger lugs allow the tire to dig deep for maximum traction when it is needed the most. The center cross split bars give good forward bite and when used on the rear allow the car to rotate better in the turns when this is desired.