Cheristin is a fast-acting topical flea treatment for cats Starts to kill fleas in only 30 minutes, kills 98-100% of fleas in 12 hours Convenient one-size-fits-all dose is good for all cats and kittens (1.8 lbs. and greater and 8 weeks of age and older) and a great addition to multi-cat households Easy-to-apply from a small applicator with a rounded tip Long-lasting (through 6-weeks) flea protection your cat deserves