16 oz, toilet bowl cleaner, deep cleans to remove rust & mineral stains, cleans & deodorizes, thick formula clings to bowl to provide deep cleaning as it deodorizes, angle-neck bottle gets under rim, safe for white & colored bowls, safe for plumbing & septic system, easy to use, flush toilet, apply liberally to all surfaces of interior bowl & under rim, let stand 10 minutes, brush bowl & flush.