High purity, seamless thimble filters offered in 5 materials. Applications include analysis of fats, oils, grease, pesticides, pollutants, organics and addititives in plastics and rubbers. Glass Fiber thimbles are made of pure borosilicate glass microfibers. These binder-free filters can withstand temperatures up to 500°C making them ideal for high temperature extractions, dust monitoring, or smoke stack gas sampling. They are acid resistant(except hydrofluoric). Thimbles have been acid washed for minimal trace metal content.