4 wire connections from 20” Apple Cinema Display to connect to an Mac mini 2014

Hi

I am trying to work out what I need to complete the connection of the above two devices.

I know which is the power cable which goes into the power adaptor and then a cable goes from there to the power socket.

I know there is an USB which goes into the back of the Mac mini.

i know that there is a DVI Cable for which I will need a converter - do you suggest a hdmi to dvi or would a minidisplayport to DVI be more suitable.

The 4th cable from the ACD is a mystery to me it has the symbol that looks like a 3 blade propellor - can anyone help me please?