2nd external monitor

I have a 15 inch MacBook Pro OS 10.12.5; 2.7 GHZ core i7. With the following graphics card.

Radeon Pro 455 2048 MB

Intel HD Graphics 530 1536 MB



I have the 27 inch LG monitor hooked up to one of the four USB-C ports and it works fine. I would like to hook up a 2nd monitor and I have a Dell with a DVI output port. (It also is equipped with a HDMI port). For $45 I bought a short cable with one end mating to the DVI cable from the Dell and the other a USB-C end. However, when I plug in to my MacBook Pro USB-C port all I get on the monitor is a message saying no DVI input is detected. Any thoughts?