Zep Commercial ZUATBC324 Acidic Toilet Bowl Cleaner quickly removes rust stains, organic and hard water stains and residue. Its clinging gel formula works longer and harder on vertical surfaces, leaving a clean shine and fresh fragrance. Zep toilet bowl cleaner is safe for septic tanks, drain lines and water treatment systems. Zep toilet bowl cleaner offers a clinging, gel-based acid formula Specially formulated to require less scrubbing Built-in squirt top Acidic toilet bowl cleaner removes soil build-up, lime-scale and other stains Minty pine scent Deodorizing formula