["Another choice for retrofitting old buildings. The NS-2 is a 2-wire IP network switch from Akuvox that provides a convenient way to upgrade analog intercom systems without the need for rewiring. Its super-long transmission distance and good compatibility with existing lines make it suitable for most old buildings. Communication: TCP/IP RJ45 port: 1 x RJ45 port, 10/100Mbps adapter 2-wire ports: 6 pairs Operating voltage: 48V or 24V Status display: 4 Installation: rail mounted Working temperature: -20?~+50? Storage temperature: -20?~+70? Humidity at work: 10%~90% Dimensions: 161 x 90 x 65 (mm) Old building retrofit", "Supports network and power supply for R20A-2 or C313W-2 via 2-wire cable", "Supports multi-level cascade through 2-wire cable", "Connects up to 6 Akuvox 2-wire IP Intercom devices", "Super long transmission distance via 2-wire cable", "Powered by 48VDC or 24VDC power supply", "rail mounted"]