For dogs between 21 – 55 lbs.. 4 month supply. Kills 98 – 100% of fleas and their larvae within 12 hours. Re-infesting fleas are killed within 2 hours. Breaks the flea life cycle. Effective up to 6 weeks. Applied between the shoulder blades on dogs. Spreads naturally on the skin surface at the hair root level. Aided by body movement to provide whole body coverage. Made in Germany. 6.5 in. L x 4.25 in. W x 1 in. H (0.2 lbs.) Water-resistant flea medication, so it continues to kill fleas even after shampooing, swimming, rain or exposure to sunlight. For dogs over 7 weeks old. Do not use dog products on cats or cat products on dogs.