The GB-250 and GB-250e Firewall Appliances are entry-level firewalls in GTA's RoBoX family with support for optional Mail Sentinel Anti-Spam and Mail Sentinel Anti-Virus add-on features, offering more power and flexibility than comparable appliances. Available in a 10 or 25 concurrent outbound user versions, the GB-250 and GB-250e are designed for small business offices that require network security functions usually found only in enterprise level firewall appliances. The proven ICSA certified GB-OS System Software, assures you full corporate level firewall security. Features include transparent NAT, stateful packet inspection, built-in IPSec VPN (optional on the GB-250 10 user version), DHCP and content filtering, all packed in a desktop internet security appliance. Total perimeter security in a small appliance.