Inserts fit wide-mouth 1.8 ml, 12 x 32 mm vials, and are placed directly in the host vial. Inserts measure 6 x 31 mm, except for TriSpring inserts which have a length of 29 mm. Flat-bottom inserts have the largest capacity. Tapered-bottom inserts allow sampling of just microliters of liquid, with nearly complete withdrawal from the tip. TriSpring Inserts - These inserts have a plastic spring attached to the tapered bottom, which centers the insert in the host vial and adsorbs shocks if the insert is touched by the autosampler needle. The Hanging Insert has a lip that rests on top of the vial. The septum seals directly and positively against the insert, reducing the risk of solvent evaporation.