A device (1) for automatic injection of a product (3) into an injection site (4), transported the product (3) for a container (50) having an open proximal end and a substantially closed distal end and It has a definite reservoir therebetween, and a needle (6) disposed at the distal end and in fluid communication with the reservoir to provide an outlet port for the product (3) of the vessel, and a piston (7) provided in the container and which is movable relative to the container, causing the movement of the piston as the product is expelled from the container through the needle, said device comprising: - a housing (8) having a generally cylindrical shape for the container , the container can be moved relative to said housing between an initial position, in which a needle tip does not extend beyond a distal end of said housing and wherein the container is in one a passive state and an active state, and an insertion position, distally spaced from said initial position and in which the tip of the needle extends beyond said distal end of said housing, preventing movement of the container out of its initial position when the container is in its passive state, and allowing when the container is in its active state, and - a safety shield (10) coupled to said housing (8) for movement between a first position and a second position in which the needle tip does not extend beyond a distal end of said safety shield, placing the movement of said safety shield (10) out of its first position the container (50) in its active state, said safety shield can (10) to move to its second position when the container (50) is in said insertion position, ensuring that security protection (10) against m proximal ovement when in said second position, - a needle shield (2) coupled to said housing (8) and covering the needle (6) before the use of said device, engaging said needle guard (2) to a member no protector (15), characterized in that: said needle guard is made of rubber or elastomeric mate
