The only solution approved for cleaning Keurig brewing systems. Clean quarterly to extend brewer life. Compatible with K-Mini, K-Duo Essentials, K- Select, K-Mini Plus, K-Elite™, K-Compact, K-Cafe, K-Duo, K-Cafe Special Edition, and K-Duo Plus. Removes mineral build-up, fast-acting and odorless. 400 mL.