These 3" probes are fully organic with active repelling ingredients of garlic and soybean oil. Just remove the rubber stopper and drop into the gopher or mole tunnel. Long lasting, once the rubber stopper is removed, the garlic odor will be evident in the tunnel for 10-12 months. If the rubber stopper is not removed, it has a long shelf life of a few years. The plastic tubes will biodegrade in about 24 months.