J.G. Finneran Limited Volume Vial Insert with Bottom Spring. Vial Insert, 50 µl, 4 x 25 mm, Clear, Glass, Conical Shape, Limited Volume, Precision-Formed Mandrel, with Bottom Spring, For 12 x 32 mm Standard Opening 11 mm Crimp Top Vials, Conical Design Permits Complete Sample Removal. View All 6 Choices.