A container for storing a product to be injected, e.g., a therapeutic or diagnostic liquid, wherein the container includes a container body and a piston body arranged in the container body in a sliding manner, the piston body moveable between a rear end position that determines a maximum filling of the container and a front end position to dispense the product, and wherein the container has a maximum opening ratio H/L of approximately 1.25 to 1.0, H corresponding to the maximum height of the container body and L corresponding to the maximum distance between the lateral wall or walls of the container body.