Shell style inserts. Cap Varieties. Phenolic Hole Cap, Temp. Limit 149°C. Autoclavable. Phenolic hole cap. Polypropylene Insert for 2 mL standard opening vial, 4.6 mm ID - Sigma-Aldrich. Insert for 2 mL standard opening vial, 4.6 mm I.D. volume 0.15 mL, conical polypropylene (with bottom spring), O.D. × H 5 mm × 30 mm, pkg of 100 ea;