Bloc Loc Half Square Triangle Ruler Set 2 - HST-SET2Half Square Triangle Ruler Set #2 contains 2 1 2", 4 1 2" and 6 1 2" multiple sized rulers. Each ruler locks onto the seam for instant ruler placement and control so that the seam ends in each corner. Trims 90% faster than a flat ruler and ruler rock is gone, too. Also trims quarter square triangles, birds in the air, y units, LeMoyne Star, double windmill, hidden squares units and much, much more! Trims in 1 8" increments.