The ZyWALL USG (Unified Security Gateway) 20 is the "third generation" ZyWALL featuring an all-new platform. It provides greater performance protection as well as a deep packet inspection security solution for small businesses to enterprises alike. It embodies a Stateful Packet Inspection (SPI) firewall, Content Filtering, Anti-Spam, and VPN (IPSec/SSL/L2TP) in one box. This multilayered security safeguards your organization's customer and company records, intellectual property, and critical resources from external and internal threats.