... absorption abilityThe material of the carving products is 'activated carbon' (Charcoal). This material has a highly porous nature ... . It works especially well to cleanse indoor air from carbon monoxide, formaldehyde, benzene and similar gas, ammonia, niton, ... product specification: 56mm X 56mmProduct craft: high quality carbon molding, gush arenaceous, with environmental protection siliceous pigment ...