Package of 30, 49 mg tablets. Each tablet treats up to 2 quarts. Purifies water for camping, boating, hiking and international travel. Active ingredient: Sodium Dichloroisocyanurate. Fast acting: water is ready to drink 30 minutes after treating. Consistently provides great tasting drinking water. Effective against Giardia Cysts, Bacteria, and Viruses. Certified to NSF /ANSI Standard 60.