Bob Martin Vetcare Flea Collar for Cats is the simple way to protect your cat from fleas all year round. o Kills flea eggs for up to 12 months; o Contains an Insect Growth Regulator to kill flea eggs before they hatch, breaking the flea life cycle; o Safe to use on kitten from 12 weeks of age; o Unique 'breakaway' safety feature allows your cat to escape should the collar become hooked or tangled. If your pet has an existing heavy flea infestation, it maybe necessary to treat your cat with a suitable insecticide in order to kill the existing fleas. Fleas are often found within your cat's basket, bedding, and regular resting areas, including carpets and soft furnishings; these should be treated with a suitable household flea spray and vacuumed regularly.