This light mounts on a MK7 extruder such as the one on a Folger 2020. You use the light holder and one of the clips. The holder has holes for three white LEDs (approx 3V each), and you should connect these up in series, with a 220 ohm resistor. The whole thing can then be connected to a 12V power supply. There are two clips. Both attach to a small piece of the screw holding the fan one exposed at the bottom of the heat sink. One clip goes straight down, the other sticks out a bit and then points the light back in at an angle. The pieces fit together a bit loosely. I use a small shim of rubber where the clip attached to the fan screw and where the clip and holder attach, and these seem to give enough friction.
The angled clip could be improved by moving the light a bit further in. Currently the brightest spot is to the right of where the nozzle is.