Check the listing for details. Ubiquiti Networks UniFi Security Gateway Pro 4 Firewall USG-PRO-4 Upgraded Fans. Condition: Used. Listed at 40.00 USD. Lightly used and in great working condition. Replaced noisy stock fans with whisper quiet fans. Factory reset and ready to adopt into your network. The Ubiquiti Networks UniFi Security Gateway Pro 4 Firewall USG-PRO-4 Retail is a high-performance firewall designed for enterprise networking setups. With the trusted Ubiquiti Networks brand, this model offers advanced security features to protect your network from unauthorized access and potential threats. The retail format ensures that you are purchasing a genuine product that has been properly inspected and certified for quality assurance. This firewall is a reliable choice for businesses looking to enhance their network security and ensure the safety of their data and systems.