Complete system ready for install - add wifi monitor to create a self-monitoring system (alerts go to you) or arrange for monitoring service. Works with copper wire telecom so excellent for any home that's not totally fiber optic. We went along with Telus's push ("we're no longer supporting this unit" - that's what happens when a big corporation buys your monitoring company ADT) without looking around for an alternative monitoring service that would have saved us having to take this out! Working perfectly when removed. LCD control panel, motherboard in locking metal case, backup battery and low voltage power supply transformer with wire terminals, remote key fobs, wireless sensors including 2 smoke detectors, 2 motion sensors, and ten door/window sensors, siren (LOUD!), 17 CR123 batteries, programming guide, and bundles of telephone wire (not from this system, but nice to have). Plenty of guidance available online for installation and programming. $120 obo.