Tisch Scientific 250 µL Micro-Insert, 29 x 5.7 mm for 9 mm Vials . Micro-Inserts are designed for consistent sampling of low-volume chromatography samples. 250 µL, Mandrel/Polymer Bottom, 29x5.7mm for 9mm vials, CV2042, 250uL MicroLiter Micro-Insert – 31*5 mm, Clear Glass, Flat Bottom. Can be used with ND8 Vials Glass shade: Clear Bottom