This oversized double-sided mat is big enough for any project. The magnetic ruler secures item to be cut during cutting process. This package includes a 16x20 inch magnetic self-healing double-sided cutting mat with a 14x18 inch cutting grid and an 18 inch magnetic metal ruler. Imported. WARNING: This Product Can Expose You To Chemicals Known To The State Of California To Cause Cancer And Birth Defects Or Other Reproductive Harm. www.p65warnings.ca.gov.