S.P.D. (Speedy Drain) is a granular caustic drain opener and preventative maintainer for paper, hair, plant fibers, food residue, grease, and fat clogs. The granular form passes through standing water to reach the blockage and catches on partial obstructions in still-flowing lines, which is why it's so effective in a weekly maintenance program. Pine-scented; no rotten-egg sulfur smell. What makes it different Sodium + potassium hydroxide blend. Most lye-based openers turn grease into hard bar soap (a worse plug). The proprietary KOH portion produces a soft liquid soap that rinses away. Coated granules. Won't cake in the container the way uncoated lye does. No aluminum filings. No flammable hydrogen gas generated during the reaction. Reaches distant clogs. Add one cup at the nearest drain, plus another cup for every additional ten feet to the suspected plug; works on outside sewers with sufficient volume. Pine fragrance. Deodorizes drains, toilets, and urinals during weekly preventative use. What it isn't for Do not attempt to clear clogs in large plastic drain pipes - excessive heat from a heavy dose can soften pipe walls. Do not add hot water on top. Do not mix with acid drain openers - reaction can boil water out of the drain. Not safe to handle without rubber gloves and eye protection. Specs & packaging Green-grey granular caustic solid, pine odor, pH ~13.5 (1% solution). Twelve 30-oz plastic bottles per case (1.88 lb / 853 g each). All packaging recyclable.