Components: barrel, plunger, needle holder, sterile needle, needle protective sheath, self-disable parts and other accessories parts. Mode: 1ml, 3ml, 5ml and 10ml Instruction 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) retract the plunger to the bottom of the syringe after application and break the plunger.