Check the listing for details. SonicWall TZ350W TZ Series Next-Generation Firewall - Black. Condition: Used. Listed at 26.99 USD. Tested, working, and reset. 30 day return policy. The SonicWall TZ350W is a next-generation firewall from SonicWALL that offers advanced security features for enterprise networking. This model is designed as a subscription service, providing reliable protection for a single device. With its sleek black design, the SonicWall TZ350W is a top choice for businesses looking to enhance their cybersecurity measures.