Telephone Multi-Tenant Entry Panel, Flush Mount. Uses phone line to call tenants. Up to 5 TL-2000 panels per phone line. Up to 2,000 primary telephone numbers and 2,000 secondary numbers can be used. Door release. Program up to 2,000 unique access codes. RS-232 connection for programming (USB-to-serial cable included). PC software included to program and update device. Connect to device directly on site or via a modem off-site.