Hardened low ash paper (max 0.02%), as an intermediate solution between quantatitive ash free paper (max 0.002%) and qualitative paper low ash (max 0.06%) for non critical quantitative works. Medium flow rate is the adequate for a general use, being the intermediate filter in terms of flow rate and retention. High wet resistance. Surface weight 80 g/m², pore 8 – 12 μm, thickness 270 μm. Available in flat disks (foiled bags of 100 disks, with no carton box), or folded (in a carton box). Equivalent to: Whatman 52