Allows user to answer door or gate from any telephone, each controller can operate two entryways, distinctive tone for each, built in call waiting, two-way communication, up to 4000' distance with Cat5 twisted pair cable, connects to 2-line/PBX/keystations, basic kit and all add-on devices operate on single pair of wire, white.
See other products in some related categories (click to browse):
Telephony, PBX & VoIP > Phone System Accessories