Model Number: TF-16Y021 Brand Name: TOPFENG Key Specifications/Special Features: Safe and sanitary toilet bowl cleaner will work to keep your toilet clean through 5,000 flushes without scrubbing!Just drop the Chem-Free cartridge into the toilet tank to prevent mineral particles from forming stains and those hard-to-remove rings around the bowl.Prevents fungus and mildew build-up, while inhibiting bacteria growth.Safe for children, pets, septic systems, and the environment.About 6" long.