1.5" x 3" Flying Geese Square up ruler, with Bloc_Loc grooves that lock on to both seam allowances at the same time. Square up your Flying Geese blocks in less time and with far greater accuracy every time! Works on all Flying Geese block methods. Never trim the top or corners off a Flying Goose again!! 1/4" seam allowance all the way round. Complete with instructions for several methods of constructing flying geese units.