What size pipe are the Blue Flame log lighters?

[rgraham]

  I'm going to be hooking up a propane log lighter inside my Pitts, and the hole looks like it's set up for 3/8ths pipe. I can't seem to find anywhere on the net that tells what size pipe the Blue Flame log lighters are, just the lengths.

  Can anyone let me know what size they are before I order one please.

Thanks,

RG