Johnson's 4fleas Spot-on for Cats and Kittens up to 4kg is a fast-acting spot-on treatment that kills fleas on contact on your cat and in the surrounding area. This treatment provides up to 2 months of protection and contains 2 vials, with each vial offering up to 4 weeks of protection. It is suitable for pets over 8 weeks of age. The dual-action spot-on treatment kills fleas and biting lice, as well as flea larvae in the area around your cat. The active ingredient is Imidacloprid. Each pack contains 2 pipettes, each preventing further reinfestation for 4 weeks, providing a total of 8 weeks of prevention. Fleas are killed within one day following treatment.