Components: barrel, plunger, needle holder, sterile needle, needle protective sheath, self-disable parts and other accessories parts. Mode: 1ml, 3ml, 5ml and 10ml Instructions for use: 1) after tearing the container, take the syringe out and screw the needle holder on tightly. 2) after removing the protective cap, draw up liquid medication into the syringe and force the air of the syringe before application. 3) when the syringe plunger is at the zero mark, pull the needle straight out of the skin. 4) press the plunger, the needle will retract into the bottom of the syringe to achieve the self-destruct effectiveness.