Teams have to use a material designed to stop spread of debris/cause of punctures
In order to prevent tyre damage to other cars, the complete endplate, with the exception of parts of the second volume inboard of the virtual endplate surface must be at least 10mm thick (being the minimum distance when measured normal to the surface in any direction) with a 5mm radius applied to all extremities.
In addition, the leading 50mm of this bodywork, with the exception of fasteners and inserts as described below, must be of a prescribed laminate, details of this laminate may be found in the Appendix to the Technical Regulations.