The Vacumed® K3 EDTA blood collection units come in various sizes, all depending on the type of blood collection situation. Some of the sizes include a 13x75-millimeter one with a 2-milliliter blood collecting capacity, another with a 3-milliliter blood collecting capacity, one with a 4-milliliter blood collection capacity, and a bigger 13x100-millimeter one which collects up to 6 milliliters of blood. All sport a violet tip cap, and are sterile.