This powerful, formulation works on the toughest weed species, yet is harmless to grass. Can also be used to kill tree stumps. You can expect to see results with just one application. 16 OZ Concentrate. Super BK32. Brush Kill. Contains 16.05% 2, 4-D & 16.1% Of 2,4-DP. Harmless to grass, yet controls 70 tough weeds.