Black Diamond Hookah Coals are 100% natural made from coconut shells. No chemicals, glues or fillers were used in manufacturing this product. Black Diamond coals are over sized cubes (25mm) and will last a minimum of 1 hour once lit. Enjoy your hookah with these eco friendly coals. These coals are a bargain since you are getting double the amount of the other brands at the same price without compromising quality.