Lowrance S3100 Sonar Module (000-15918-002)S3100 module, required for Active Imaging HD on Elite FS HDS LIVE Carbon. Lowrance S3100 Sonar Module (000 15918 002) The Lowrance S3100 Sonar Module is required to run Active Imaging HD on Elite FS, HDS LIVE, HDS Carbon, and HDS Gen3 displays. CRITICAL: HDS PRO does NOT need the S3100, it has native Active Imaging HD support built in. If you have HDS PRO, you don't need this module. Key Features External Sonar Module Enables Active Imaging HD on