s than 42mm Diameter produced with sawdust briquette of 55mm Diameter. This grading is to ensure all manufacturers to properly char their product. The charring temperature too has to be raised to as high as 800 - 1000 Deg C in order to have the required metallic sound when rolled on floor (the same specification for the Japanese White Charcoal). With the above stringent requirement, the buyer will never received partially charred charcoal compared to any wood charcoal(some carry wood base)