What size is BOV vacuum line?

[C'ville]

I want to install my blitz turbo timer/boost gauge this weekend but I need to get a T-fitting for it.
The vacuum line that came with the blitz looks like 1/8" very small.
The tube on the BOV looks like 3/16" maybe.
Anyone know what size T-fitting they used?

Thanks,

 

[Wes]

The fitting on the stock hose I used 1/4 and the outlet to the gauge was 1/8.

If that makes sense. Had to zip tie the stock hose down pretty good though even with 1/4.