Comodo EssentialSSL Wildcard

The EssentialSSL Wildcard certificate is a great value for small and medium-sized businesses. Because it's a wildcard certificate, you can quickly and easily secure an unlimited number of sub-domains of the same domain name. An EssentialSSL Wildcard certificate issued to *.yourdomain.com is valid for: www.yourdomain.com, secure.yourdomain.com, mail.yourdomain.com, etc.