The Tightvac Storage System Set of 3 Vacs are nested inside each other and have a unique vacuum seal closure system, which allows moisture to escape, keeping your goods dry and oxygen free. Set of 3 includes these sizes : TV3 (0.57L,45g), TV2 (0.29L, 25g), TV1 (0.12L, 10g). Amounts held by each container may vary with the product you store. The 6 oz. Tightvac is the perfect size storage for snacks, pet treats, 16 oz. of sugar, tea, nuts, trail mix, cookies, 45g of herbs. Great for travel. The 3 oz. Tightvac is the perfect size storage for snacks, pet treats, vitamins, homeopathic remedies, herbs, prescription drugs, cosmetics, jewelry and it would hold 25g of Medical Herbs. The 1.5 oz. Minivac is a perfect pocket & purse size storage container for vitamins, homeopathic remedies, prescription drugs, cosmetics, jewelry and would hold 10g of Medical Herbs. The Tightvac easy to use patented system creates a vacuum seal simply by pushing the button on the lid as you close it/press button to open, simple! Note: For Medical herbs that are sticky we recommend using a bag inside the Vac. This keeps the area clean where the body and the cap meet. Thus maximizing the efficiency of use and longevity. The Vacs tend to keep goods dry - A moisture disk may want to be used according to personal taste.