... quickly, burning time: 4-5 hours, easy deliming, white ash, the content of ash: 2.6% -3.6 ... a very refreshing sound of metal steel when charcoal knock charcoal, good hardness, specific gravity:1.3-1. ... quickly, burning time: 3-4 hours, easy deliming, white ash, the content of ash: 2.6% -3.6 ... little bit refreshing sound of metal steel when charcoal knock charcoal, good hardness, specific gravity:1.1-1. ...