T-Sac filter #4 is for cups, mugs and glasses with up to two teaspoons of tea. Enjoy loose tea much more easily versus using a traditional tea infuser. Convenient for home, work and travel and are great for the environment, too. Made with biodegradable, unbleached manila hemp, T-Sac is an all natural, chlorine-free, 100% biodegradable hemp sac for brewing loose teas. T-Sac can also brew single serve coffee dependent on the grind.