Ideal for 2mL HPLC Autosampler vials in 12mm diameter and alternative similarly-sized test/culture tubes like 1.5ml/1.8ml/2ml cryogenic vials and centrifuge tubes Each hole is clearly marked with numbers and letters, indicating the coordinate position of the sample vials, that is convenient to the accuracy and economical conduct of the experiment Vial rack will be stacked within the empty or stuffed with a collection of vials,Save area by stacking several plastic ampul racks on top of every other Polypropylene phial racks ar proof against most solvents. Autoclavable 250 degrees F and 15psi for twenty minutes