No dot is any good if it doesn't hold zero. MOA is minute of angle, that is the diameter the dot covers at a given yardage. One MOA covers approx. one inch at 100 yards, two inches at two hundred yards. So, a red dot that has an MOA of 4, the dot will appear to cover approx. 4 inches at 100 yards, 8 inches at two hundred yards. A lot depends on if you will be shooting from the bench, off hand, hunting and the distances. Moving the sight from one weapon to another will generally require the dot to be re-zeroed.

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