Will not work without an NEC SL2100 phone system controller. Will not work on a plain phone line. This is a digital phone, not IP or VoIP, despite IP being in the model name. It wires directly to the SL2100 phone system controller.

Black, aka charcoal, IP7WW-24TXH-Tel-(BK) SL2100 phone by NEC. New handset cord and a used label.

Tested on an NEC SL2100 phone system prior to shipment.