These screws need a jeweler's screwdriver or similar - countersunk Phillips head. Metric dimensions are nominal and specified as Overall Length x Shank Diameter Under Head x Head Diameter. See below for size and gauge code.
KARTELL - Italian made laboratory ware. Screw caps with inner security seal. Wide mouth body which is suited to powders. Notes can be inserted under lid and above seal. - HDPE - see table below for suitable uses.