On January 6, 2023 at 14:18, SWOInstaller said...
It's just a different way of writing 2/3 or .066".
In all honesty it is 4" OR 6" deep for the people that may take 4/6" as an actual measurement
One of my interview questions for installers is to tell me what half of 7-1/8" is. After telling me about all the tools and his proficiency, I had a guy come back to me with some answer that included 2/5. Yes, two fifths. Thus proving he's never used a tape measure and ending the interview.