This collar is designed for large breeds of dogs over 12 weeks of age. This brown collar is unaffected by water and will kill fleas and ticks for up to 5 months. Tick preventing products may take several days for a lethal quantity of insecticide to be absorbed. The ticks occasionally will remain attached even when dead if this should occur they should be left to fall off naturally removed using a purpose built tick picker or removed by a Veterinary Surgeon. If tick prevention products aren't used the tick once full will fall off when and where it wants to this could be outside or in your home once hungry it will then reattach itself onto the next victim.