4 Channel 3G SDI Input Card for Multimedia 16 x 16 Matrix Switch (500470). The SDI Input Card (500473) is a 4-channel module for MuxLab's Multmedia 16x16 Matrix Switch. The card allows up to four SDI sources to be switched and/or distributed via Cat5e/6 cable. The 500473 converts all SDI channels to HDMI format for transmission via the HDMI and/or HDBaseT output cards. The card features four BNC inputs and four BNC loopback connectors.