Whatman Polycap 36TF Capsule Filter, 0.2um (NO filling bell), non-sterile (may be autoclaved once), hydrophobic PTFE membrane filter. TF = Solvent Chemical Resistance. $90.00. 6700-7502. Whatman Polycap 75TF Capsule Filter, 0.2um (NO filling bell), non-sterile (may be autoclaved once), hydrophobic PTFE membrane filter. TF = Solvent Chemical