Line Bone (Bag of 2) by Stringliner Save Liquid error (product-badge line 32): Computation results to '-Infinity'% $5.95 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart Allows you to set a level course line when building a concrete block wall. Stringliner carries accessories for the masonry trade. These masonry must-have products are used by professional masons and bricklayers every day.