Rolex Explorer: Real or Fake?

[Cilogy]

Hi I'm new here. I just got a Rolex Explorer from my grandmother and I want to determine whether or not it is real. I love wearing a watch, but I never liked metal watches nor even Rolex watches for that matter. However, I've really grown to like this one, especially since it belonged to my grandfather before he passed away.

Here is a pic, I can take more if anyone wants different angles:

http://i.imgur.com/0Q0Wn.jpg

From what I know, my grandfather had it since about 2005 or 2006, so I'm guessing it's about that old. I've searched around on ehow.com and a few other sites about how to spot a counterfeit Rolex, and so far there are no signs it is fake, but the second I heard that my grandmother got it from China, I was a bit skeptical. I thought I could get some advice from you guys on this forum. Thoughts?