The ProHD comes with a cable that splits out with 4 IR "emitters". You would basically secure each emitter at a point where the IR LEDs face the IR receiver window on the device being controlled. You can control up to 4 devices (DVR, cable box, PS2, etc) The 1/8" jack on the back of the ProHD is where the IR emitters plug in. Pretty simple. I don't know what you'd do if you had to control a box that was set up to receive VHF remote commands.
Hope this helps.