'71 XKE S2 OTS Door Drain Hoses

Hi All,

Need to install new door drain hoses in my friends doors. What is the correct diameter for these hoses? Many thanks!

I ended up using 3/8" diameter hose. Was able to attach to the metal tube with a bit of force. This is good because it wont fall off. Also seemed to fit well in the lower holding clip.
Regards, Bob