PCV Hose
 

Can anyone tell me for certain what this hose is? Is it 1/2" or 5/8"? I have read 1/2" but when I look at the barb on the PCV, it is exactly the same size as the barbs on a 5/8" hose fitting I have. But that is a multi-barb fitting and the PCV is a single barb so maybe they made the PCV barb larger to get a better seal.

Also, what is the thread size on the PCV? It looks like 1/4" NPT but I want to see if anyone knows for sure.