Plumbing ID?

[forestsofkelp]

I want to buy a solenoid (LeakBlock Sensor) to turn off this fixture in case of a leak. I don’t know how to tell if it’s 3/8 or 1/4in. Any ideas what size it is?

 

[hoffmeyerz]

That blue line is 1/4" OD tubing

 

[forestsofkelp]

thanks for the response. I was trying to figure out the threads for the metal fixtures.

while writing my response to you I realized the valve comes with quick connect fittings for OD tubing, so I was asking the wrong question, but you gave me the right answer.

thank you for the solution.