Whats the standard size 3/8 for faucets hoses/supply line

[norbertojahn]

Hello, we have been trying to find out whats the correct 3/8 size for faucets. Check the attached picture. What is the difference between these 2 sizes? These both were supposed to be 3/8. Its driving me crazy kkkk

 

[On Point Piping]

1/2 "

 

[Sponsor]

 

[On Point Piping]

1/2 "

One side 1/2" to the faucet , other side 3/8th to the speedy valve