Doff 24/7 Superfast Weedkiller is a ready-to-use, non-selective weedkiller spray with pure contact action on all green plants. Pelargonic acid is its active ingredient. Convenient ready-to-use spray bottle. Designed for spot weed treatment on all common garden weeds growing on patios, paths and borders. Results are usually visible within 24 hours as a significant withering and browning of the leaves. For best results, apply to small actively growing weeds. Application may need to be repeated at 2-4 week intervals.