Labasics Qualitative Filter Paper Circles, 55 mm Diameter Cellulose Filter Paper with 15-20 Micron Particle Retention Medium Filtration Speed, Pack of 100: Amazon.com: Industrial & Scientific
WHATMAN 55mm Circles Grade 1 11μm Medium Qualitative Filter Paper 1001 055 | eBay
1001-055 - Grade No 1 Filter Papers 55mm - Whatman
CYTIVA WHATMAN, High Quality Cotton Linters, 41 - Ashless, Quantitative Filter Paper - 32HH88|1441-110 - Grainger