The micro inserts have a small total volume capacity of <400 µL and can be classified as either Polyspring, conical, or flat-bottom within the SureSTART Collection. Micro inserts are placed and sealed inside a vial so they can be used in conventional autosampler racks. The smaller 6 mm diameter of the insert gives better sample recovery than a routine flat based vial with conical inserts being most effective with residual volumes of 1-2 µL. Many are held in place by a Polyspring, which cushions and centers the insert.