Bulkhead size hole ?

[redrider736]

I bought a sight glass kit that comes with a 1/4" bulkhead, and I have two 1/2" bulkheads for the Ball valve and Thermometer.

Sorry if this a stupid question. How large of a hole is needed for a 1/4 & 1/2 inch bulkheads ?

 

[Bobby_M]

9/16" and 7/8".

 

[redrider736]

9/16" and 7/8".

ThX Bobby !! It was your Kit that I bought.