The st121rgb vga over cat5 video extender receiver is specifically designed for use as the receiver unit to the startechcom st1214tgb 4 port vga over cat5 utp extender transmitter allowing you to split and extend a single vga source to up to four remote displays from the transmitter device the vga video signal is sent over standard 4 pair category 5 or better utp cable to remote monitors each connected to an st121rgb cat 5 vga receiver supporting distances of up to 150 meters 500 feet