Graal Jar is the smart solution to preserve the natural essence of your plant products for longer.the unique properties of Graal jars in violet biophotonic glass filter out ultraviolet and infrared light frequencies to protect and revitalise natural products, greatly extending their shelf life.its airtight closure prevents aromas from dispersing into the environment, keeping the fragrance intact for longer.its integrated thermo-hygrometer in the lid helps you constantly monitor the humidity and temperature conditions inside the jar to know at all times how the contents are preserving. Its integrated thermo-hygrometer in the lid helps you constantly monitor the humidity and temperature conditions inside the jar to know at all times how the contents are preserving.Graal jars in different sizes will help you better preserve medicinal herbs, infusions, tea, truffles, coffee and other natural products only thanks to its violet glass, designed specifically for this purpose.