Apr 27, 2023 · The inside diameter of vials vary with the manufacture. The following insert part numbers are compatible with these large opening vials. 29435-UPK100, Certified 200 μL glass inserts, mandrel precision point, 6 X 29mm, with bottom spring; 29436-UPK100, Certified 250 μL glass insert, conical bottom, 6 x 31 mm