*4.2.1.2.2 FSN acupuncture needle core*

The needle core consists of a stainless steel needle and a hard-plastic core, as shown in **Figure 2**. This part insures the FSN acupuncture needle to reach enough rigidity to enter the body quickly and to complete sweeping movement. The stainless steel needle tip is beveled. On the base, there are 10 protuberances which are on one side. When the convex protuberances are upward, the beveled tip of the needle is also upward. The surface is in line with the tip of the needle, the front end of the needle has a longitudinal groove, and the front of the groove has a transverse slot on the right side, which is used for fixing the soft casting tube during performing a sweeping movement.

#### *4.2.1.2.3 Soft casting tube and base of FSN acupuncture needle*

The soft casting tube covers the stainless steel needle (steel needle inside, soft casting tube outside). The soft casting tube is fixed to the plastic socket through the built-in rivets, as shown in **Figure 2**. The casting tube of FSN acupuncture needle has a bump, which is matched with the grooves in the core seat and the slot. The protuberances on the base are placed at the bottom of the groove when we sweep the needle.

The main function of the soft casting tube:


#### *4.2.1.2.4 Protective sheath*

To protect the stainless steel needle and soft tube from the impact of the collision, we designed a protective sheath. The protective sheath is used to protect the aseptic state, as shown in **Figure 2**. After the sweeping movement, the solid needle should not be discarded. It must be put back into the protective sheath to prevent puncturing oneself and others.

*4.2.1.2.5 Length, diameter, appearance, and preservation of FSN acupuncture needle*
