2 Line- Expandable Digital Receiver -Supports up to 7 line card modules -256 event buffer per line -Listed UL and ULC for commercial fire and burglary -19" rack mount includes: SG-CPM2 Central processing module SG-DRL2A Digital line card module SG-MLRF receiver cage -Supports: SG-DRL2A Digital line card module SG-DVL2A DVACS line card module SG-DRL-IP Network line card module