Johnsons 4Fleas Tablets For Dogs and Puppies ---Puppies and dogs over 4weeks ---Up to 11k dogs and over 11kg dogs ---starts killing in 15mins ---Lasts 24 hours ---Safe to use with other treatments Johnsons 4Fleas Tablets kill Fleas on Puppies and Small Dogs over 4 weeks of age and weighing up to 11kg. The other pack does larger dogs over 11kg. The 4Fleas Tablets start killing Fleas in 15 minutes and kill all fleas on pets in 24 hours and are safe to use with other flea and worm treatments. Please be aware as the 4Fleas tablets only kill adult fleas, for complete flea protection we advise you to use this product in conjunction with a Spot On that can offer longer lasting protection. Household Treatment Spray should be used as well. This pack contains 3 treatments.