Torx size for HDD rails

[SBird]

I was wondering if anyone knew what size torx wrench needs to be used for the rails on the HDD in the unibody MBP? Is it a T6 or T8?

 

[Bill Gates]

T6. Two of the screws on mine were a slightly different size and I had to use a different bit from my screwdriver kit, but I don't know if it's supposed to be like that.