Each tin contains 2 individually wrapped, 6 month collars for 12 months of maintenance free protection from fleas & ticks Flea & Tick Collar for large dogs - Each tin contains 2 individually wrapped, injection molded, 6 month collars for 12 months of maintenance free protection from fleas & ticks. Easy-to-use Salvo™ flea and tick collar quickly and effectively protects dogs from fleas and ticks. Fleas on the dog are killed and fleas in the dog’s environment that may appear on your pet will be killed. The odorless Salvo collar is specially formulated using insecticide release technology which works with the natural oils in your dog’s skin to distribute the active ingredients over the dog’s body. The collar should be worn continuously. Reapply a new collar every 6 months.