Talk:Randuin's Omen/@comment-84.113.65.130-20120206142224/@comment-4087140-20120206235350

Duration = 2(ArmorMR)/200.

To answer your question: 4{{times}0.5 seconds. It combines the two, as far as I understand. I haven't explicitly tested it, but it would be very strange if it didn't work that way, based on the description.