Ⅰ. Wall thickness of 1.5mm, hexagonal stamping technology: the sleeve is thickened and not easily deformed. Ⅱ. Horizontal positioning of the leather rings ceiling for more precise leveling, and the ceiling will no longer tilt. Ⅲ. Straight concentricity, stable hexagonal handle design: high concentricity, not easy to shake. Ⅳ. High temperature quenching process, sturdy, and rust proof: high hardness, toughness, and strong hardening treatments. Ⅴ. Integrated forging, sleeve body made with light alloy steel leveling sleeve: with high hardness, toughness, and strong hardening treatments. Ⅵ. Multiple specifications to choose from to meet daily needs: the ceiling will no longer tilt. Ⅶ. Specifications: Material: Chromium plated iron Ⅷ. Size: 10mm, 12mm, 13mm, 14mm, 17mm (optional) Ⅸ. Package Includes: 1PC Lengthening Hollow Screw Rod Ⅹ. note: 1.Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you place order. Ⅺ. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you.