It is mainly used in stack monitoring of emission. It is most convenient and ideal for dust collection due to shape, which minimizes the loss of impurities in handling. Micro glass Fiber thimbles are produced from 100% Borosilicate glass fiber. It is binder free structure, no leaching of extractable occurred during critical analysis. High dust holding capacity of thimbles facilitates to achieve large through put. Unlike Cellulose 0 thimble, it can be used at higher temperature (500 C).