64 oz container. * Treats drains before they become clogged with a unique formula containing natural enzymes and bacteria. Drano® Max Build-Up Remover helps prevent clogs from blocking your pipes. Use it on a monthly basis to help prevent plumbing problems and keep your drains running smoothly. The more build-up you remove now, the less likely it is that you will need a drain cleaner to unclog your drain * later. Won't harm pipes, garbage disposals or septic tanks. Contains no phosphorus.