The Cisco SA520 Security Appliance is now obsolete (past End-of-Life and End-of-Support status).
End-of-Sale Date: 2013-04-16
End-of-Support Date: 2016-04-30
Cisco's End-of-Life Policy
You can view a listing of available null offerings that best meet your specific needs
If you want support information for the Cisco SA520 Security Appliance documentation, it may be available through Cisco.com Search or in the Cisco Community