29*5mm Polypropylene Micro Vial for Small Opening Vial. Vials, Racks, Holders, and Lyophilization Containers. Vial Rack. This rugged polypropylene rack holds 48 vials, size 1 dram (15 x 45mm), or 4 ml tissue culture vials, or 2ml serum vials in 4 x 12 configuration with alpha-numeric indexing. The rack is constructed from chemically resistant