Multiple-sized HST ruler 4 1/2″ x 4 1/2″ trims all types of half-square triangle units quickly, easily and with precision while controlling where the seams go.

Bloc Loc’s Half-Square Triangle 4 1/2″ x 4 1/2″ ruler locks onto the seam for instant ruler placement, control so that the seam ends in each corner and trims 90% faster than a flat ruler. Ruler rock is gone, too! Also trims quarter-square triangles, birds in the air, y-blocks, LeMoyne Star, double windmill, hidden square units and much, much more! HST ruler is multi-sized and trims in 1/8″ increments.