The PDF would not send but here it is that better explains the answer.
The most important thing to do is use the Field of View (FOV) for a comparison as all companies have different ideas of what 1x is.
The IR HUNTER MKII is available only as a 640x480 resolution so to compare to a 320x240 it would be the 2x zoom. Also a D740 NV weapon sight has a 10° FOV and a D760 is at 8° FOV which you can see below of where it would compare to the IR HUNTER models. Please note that your resolution breaks down as you increase digital zoom magnification.
Model 1x 2x zoom 4x zoom 8x zoom
IR HUNTER MKII-20 22° 11° 5.5° 2.8°
IR HUNTER MKII-20 12.5° 6.3° 3.1° 1.6°