The filter papers are world-renowned as the standard for laboratory filtration and are associated with quality, reliability. Made from high-quality cotton linters, which have been treated to achieve a minimum alpha cellulose of 98%. Used for general filtration and exhibit particle retention levels down. Used in qualitative analytical techniques to determine and identify materials. Specifications Shape: Circles Material: Cellulose Size: 63 mm dia. Weight: 0.3968 lbs - SKU: MDP13167