Urgent - can somewhere measure the diameter of a hydration bladder pipe?

[zebra]

Urgent - can someone tell me the measurement of a hydration bladder drinking tube - I need it to pass thru an eyelet, and there are two sizes available: 12mm or 16mm inner diameter?

Thanks!
Chris

 

[Pappa-B3r]

 

[Brewse]

 

[zebra]

 

[zebra]

 

[Brewse]

 

[zebra]