Sterile Technique: Ethylene Oxide Gas Sterilization. Gun Material: PC. Stud Material: 316L Surgical steel. Ear Stud Gauge: 3mm/4mm/5mm. Packing: 1 piece gun with 1 piece ear stud individual sterile packed. Feature: 1. Each unit combines self-destroying ear-piercing gun with a built-in ear stud. 2. It is individually packed and sterilized according to the standard medical requirement. 3. It is designed mechanically so easy to use that you can even do the ear piercing by yourself! 4. Individually packed and sterilized, avoid inflammation. 5. Disposable, no cross-infection, no hepatitis, no HIV. 6. Easy to operate, easy to locate the pinpoint where you want the hole to be accurately.