1. Fastened with stainless steel inner hexagon double screws, firm and not easy to loosen
2. High-strength aluminum alloy material, lightweight design
3. Surface frosting process, bright color
4. Material: aluminum alloy
5. Height increase: about 8.5/11.4/14.4/17.5cm
6. Size: 8.5cm about 11.5x2.86cm, 11.4cm about 15x2.86cm, 14.4cm about 18x2.86cm, 17.5cm about 21.2x2.86cm
7. Weight: about 167g for 8.5cm, about 219g for 11.4cm, about 258g for 14.4cm, and about 301g for 17.5cm