The glass syringe is used for epidural anesthesia because the glass syringe is lubricated when it encounters water, and the injection does not have much resistance, and it can be injected evenly. If it is a plastic syringe, the resistance is relatively large. It is mainly a test method for entering the epidural space. The plastic syringe has a large resistance and no feel. There will be a rupture of the membrane when entering the epidural space, and the glass needle will only suck back with a slight piston.