Are either the high or low mounts absolute cowitness? — 2 Answers

This is based solely on estimates, from magnifying the provided images and counting the pixels. Just looking at it, though, neither one is absolute cowitness, and neither even comes very close.

Assuming the ring's ID is exactly 30.0mm, the low mount has a center height of 1.07", well below cowitness but too high for a T2 pattern optic that isn't on a riser. A 1/2" riser for the T2 would bring it up more or less in alignment with the low mount.

The high mount's center height, I estimate to be about 1.66", at the very top end of "lower third cowitness." As an aside, I really dislike the term "lower third cowitness" because the people selling the mounts and risers put that label on anything that has a center height between about 1.45" and 1.65" above the rail. Try lining up a dot sight that's 1.45" up with a magnifier that's 1.65" up and you'll see what I mean. When both are sold as "lower third cowitness," the term is meaningless.

...of course, people sell stuff as "absolute cowitness" that's got a center height anywhere from 1.38" to 1.55" or higher, so that term doesn't mean much either. Is it so hard for the people who make these products to supply potential customers with actual numbers?