Inserts for 2.0 mL, 11 mm Crimp-Top, 2.0 mL, 9 mm Short-Cap, Screw-Thread, and 2.0 mL, 10 mm Big Mouth Screw-Thread Vials. Aijiren Technology Low Volume Insert with Plastic Spring, 300 µL, 6 x 29 mm . Vial inserts are a solution in applications where there is limited sample volume. Choose the appropriate volume insert for your sample volume and vial size