Search for "Symantec Endpoint Protection" and select the latest stable release version (such as SEP 14.3). Within the download package list, you will typically see two primary options:
Provides the same high-level, multi-layered defense (Insight, SONAR, Firewall, IPS) as the enterprise version.
Download the daily .exe or .jdb definition file corresponding to your SEP version (e.g., Certified Definitions for SEP 14.x).