Abstract: A drug delivery device is disclosed, wherein the device comprises a housing; a cap located at a proximal end of the housing, the cap including a first pair of deflectable arms and a second pair of deflectable arms; a product vessel arranged in the housing, and a needle coupled to a distal end of the product vessel; a plunger rod for dispensing a product from the product vessel, wherein the plunger rod is slidably received within the cap and partially disposed inside the product vessel; and a needle cover at least partially disposed in the housing, wherein the first pair of deflectable arms are configured to deflect radially inwards towards the plunger rod and the second pair of deflectable arms are configured to radially outwards away from the plunger rod.