Replacement O-Ring For Surefire E1L Outdoorsman

[:)>]

Does anyone know the size o-ring that I need to get to replace on on my E1L? I tried Home Depot and a #13 looked to be the right diameter but it was too thick and would not let the head screw down to the body enough for the battery to make contact.

 

[Splitrail]

Does anyone know the size o-ring that I need to get to replace on on my E1L? I tried Home Depot and a #13 looked to be the right diameter but it was too thick and would not let the head screw down to the body enough for the battery to make contact.

Surefire?
Battery Junction?