Capable of handling 72 zones, while partitioning up to seven separate sub-systems plus a common area, the XL4 is perfect for any home, apartment or business. Wired for eight zones, the XL4 also supports a two-wire multiplex bus expansion, which is capable of handling an additional 64 zones. A fuseless design eliminates unnecessary service calls. And, with powerful features like a 128-event log, 64 user codes and seven authorization levels, the XL4 gives you the flexibility you need to meet the most demanding applications.