Spectra Shield® Collar Attached Medallion quickly clips to your dog's collar to control fleas and ticks for four months. This simple device clips to your dog's collar without any messy topical applications necessary. This handy medallion is available in three sizes for pets of all sizes. Spectra Shield® Collar Attached Medallion beats out other forms of flea and tick control: •Spectra Shield® offers four months of protection. •Forget about having to apply a topical treatment every month. •This medallion can be safely worn even when swimming or bathing! •With this medallion's sustained release delivery system, the medallion continuously releases very small amounts of active ingredients. •Spectra Shield® requires no special activation or maintenance, just clip and go.