Sorry.. Which Mod is it???

[Jackelmyer]

Gah, I've had the mod name once and now can't figure it out or find it. 

 

Which mod is it that makes it so you can run a fuel line from one ship to another and transfer fuel?

 

[Superfluous J]

There are 2 that I know of:

Kerbal Attachment System has a whole bunch of stuff, including the aforementioned fuel lines.

DMagic's EVA Transfer is just the tubes, with its own transfer UI. I'd suggest this one.

Oh! And Simple Logistics. I've not vetted this one yet but it looks intriguing. Lets you transfer fuel without actually hooking up the lines, and does it automatically based on how you set up the logistic network.

[Jackelmyer]

Thank you!