Alternative to a private branch exchange (PBX) phone system, smaller, cheaper, but less flexible. Allows a caller to directly select outgoing lines, incoming calls, or use intercom and conference facilities via several buttons. A user does not have to dial ‘9’ to access an outgoing line as with PBX, but does not have automatic routing of incoming calls. A KTS is user-installable, handling multiple lines with no surcharge to the telephone company. However, a hunt-group service is not available.