Mathey Dearman Flange Line Up Pins - "FLUPs" assist the pipefitter in aligning flanges for welding quickly and accurately. FLUPs are available in both slide-locking, and wobble-nut models, and are constructed from Stainless Steel. This is one of the best 2 hole pin you can find.
Make sure you order 2 to get a set. They are sold as singles.