"A complete urinal maintainer with screen and chemical block bonded together. Acid helps keep urine deposits (which will eventually clog the drain) from forming. A concentrated dehydrated acid bowl cleaner to be activated by moisture contact each time a fixture is flushed. Keeps drains open, deodorizes air space and protects surface by depositing a wax coating and by releasing an enzyme that digests organic material. Easily disposable. Fits all urinals. Lasts 30 - 40 days. Each time the fixture is flushed, a pre-measured amount of chemical compounds and powerful cleaners is released that descale, delime and deodorize the fixture and drain lines. Uni-Tab should not be placed so that it is completely submerged in water as this will drastically cut down it's effective life. "