An improved safety feature for preventing overdosage to a patient is disclosed. In one embodiment, the feature includes an improved screen member that prevents the inadvertent entry of a needle having too large a diameter. The screen member includes a plurality of holes that are configured so as to rid unwanted dead spaces that can damage an injection device during injection. Another embodiment of the safety feature includes a plurality of pins situated so as to similarly create a plurality of openings for reception of certain sized injection devices. Methods of providing a bolus dose to a patient are also disclosed.
