Why aren't the flacons of Kmax keratin fibers completely filled?

The flacons are not completely filled because we keep the empty space necessary to vigorously shake the product in order to produce the electrostatic charge necessary for the fibers to link to natural hair.

Anyway, the fibers' amount contained in the flacon is always slightly higher than the one shown in the package, because the packaging machinery is calibrated to a greater quantity than expected.