To begin, cut a 30-centimeter polyethylene PE-30 tube. Carefully insert about three-fourths of the 25-gauge needle into one end of the tube. After preparing a 1-milliliter syringe, fill it with sterile 0.9%sodium chloride solution, and connect it to the 25-gauge needle.
Then, gently infuse saline to check for a proper round tip and no leakage from the ends of the needle. Prepare two steel wires, each 20 centimeters in length. Then, insert a 25-gauge needle on one side of the wire.
Use solder to attach the pin to the other end of the striped wire.