Cap Material Polyethylene. Sterile No. Height (in) 1 49/64. Outside Diameter (in) 19/32. Height (mm) 45. Outside Diameter (mm) 15. Description Shell Vial, 15 mm, Polypropylene, Flat Bottom, 4 mL, with PE Plug; 1000/pk. Key Features. Polyethylene plugs give a tight seal yet are easy to insert or remove.