A 2U network rack refers to a standard server or equipment rack enclosure with a height of 2 rack units (U), commonly used for mounting network switches, DVRs, routers, or CCTV servers in compact setups like your security installations. "Voltaic Cable" likely indicates a branded or generic accessory bundle (e.g., power/data cables) sold alongside these racks by Indian wholesalers for easy cabling in racks.
 
Height: 3.5 inches (88.9 mm) total rack space.
Width: 19 inches (482.6 mm) external mounting standard, internal ~17.5 inches.
Depth: Varies 15-36 inches (38-91 cm); common wall-mount models like D-Link are ~40 cm deep x 55 cm wide.