An auto-injection device including a housing, cartridge, needle, and needle cover. The housing includes longitudinally extending flexible arms. The cartridge moves relative to the housing and contains fluid medicament. The needle is at a proximal end of the device. The needle cover has openings along the longitudinal direction and moves between a first position, a second position, and a third position, wherein the needle is unexposed in the first and third positions and in the second position the needle is exposed. The needle cover is biased towards the third position. An abutment on the at least one longitudinally extending arm of the housing is receivable within the at least one opening along the longitudinal direction of the needle cover when the needle cover is biased into the third position.
