Pathclear Gun! Weedkiller contains a Systemic weedkiller and contact weedkiller to kill off all manner of existing weeds and residual weedkiller to prevent new weed seeds from germinating. Pathclear Gun! Weedkiller has been specially formulated for gravel paths and drives. Works at the leaves and roots to stop new weeds growing for up to 3 months. It is effective against annual and perennial weeds.