I know this is not AR15 related, but have come to trust the advice and knowledge on this board. I am thinking of picking up a Hensoldt scope for my HK91. I saw that Cheaper than Dirt shows 3 different scopes:

Hensoldt ZF 4x24 Model 1 - $299
Hensoldt ZF 4x24 Model 2 (accepts reticle Illuminator) - $349
Hensoldt FERO Z24 (Illiminated Reticle) - $399

So...I'm wondering what the difference is between the ZF Model 2 and the FERO Z24?

Thanks!