Craftsman 5 pc. Flare Nut Wrench Set Standard SAE
Sears Item# 00942012000 | Model# 42012
The go for $34.99 at Sears.com and I used them to start taking off the flare fittings after I was simply stripping the nuts with standard wrenches.
You can buy one double ended wrench for like $21, but for another $14 you get a complete set of 5.. better deal.
I was going to try the Harbor Freight flare nut wrenches for $10 but wwaaayyyyyy to many forums were all saying the same thing.. they sucked.