Weed Weapon contains two active ingredients of different types. These actives, glyphosate and saflufenacil, work together in what is called a synergistic way; improving the efficacy of both when used together.
The use of two active ingredients also means that it will control weeds that might be resistant or tolerant of glyphosate alone, and it greatly reduces the risk of development of resistance in weeds.
Resistance to herbicides through overuse of the same single active ingredient is a concern for farmers, horticulturalists and gardeners. It is good practice to use products that combine actives of different types to prevent resistance developing.