Very poor paper, warped (see image), does not seal with Buchner funnels, does not tolerate cold substrates, very inflexible for a quantitative article that needs to be flexible, manipulable, but not particularly rigid. Look for "Lab Nerd" filters for high quality "quantitative" and "fast" compaction on Buchner funnels. I think Scientific of Houston is a good supplier, I just think that "Double Rings" company sells terrible products. You don't have to spend money on products that don't match their description.
NANPU Air Drying System With Double Filters And Pressure Regulator Combo For Clean And Controlled Air Supply
18 Review
NANPU Compressed Air Filter Regulator Combo: Brass Element, Semi-Auto Drain, 0-150 Psi Gauge, And More
21 Review
NANPU 1/2" NPT Air Drying System - 5 Micron Particulate Filter, 0.01 Micron Coalescing Filter, Air Pressure Regulator Combo - Semi-Auto Drain, Poly Bowl W/Metal Gauge
23 Review
NANPU DFR-02 1/4" NPT Air Drying System - Double Air Filters, Air Pressure Regulator Combo - Semi-Auto Drain, Poly Bowl
20 Review