Dell™ Sonic WALL™ NSA 250M & 250M Wireless-N high-performance, modular Next-Generation Firewalls offer branch offices & distributed enterprises in-depth frontline security, application & user control, network productivity & optional 802.11 dual-band wireless. The NSA 250M acts as the first line of network defence against viruses, Trojans, key-loggers & other application layer attacks, without compromising network performance. The NSA 250M Series can be extended with a variety of modules to provide deployment flexibility & reduce acquisition & maintenance costs.