- You Choose Your Size - These jars come in 3 possible sizes - Large 2 oz, approximately 8” x 4”; Medium 1 oz, approximately 6” x 3”; and Small (portable) ½ oz 4” x 3”. Take your pick for your particular use. - Airtight Storage You Can Count On - Kozo brings you a precision-designed, black glass-safe container where you can safely store your stash. This UV Protected container has an airtight lid, which ensures that all flowers stay fresh. - Enhancing The Quality And Freshness Of Your Buds - The Kozo 2-Way Humidifier is a maintenance-free solution that requires no activation. Each packet contains a specially prepared saturated solution of water and natural salts for the most purified humidity control. - Great Quality, Build To Last - Yes, although these airtight jars are made of glass, be assured that they are really tough. We know they’re going to get a lot of use and particularly in the case of the small ½ oz size, they may do a lot of traveling.