| Company | Timeline | Status | |
| Powermaster Service Limited Director • Engineer | 31 Jan 1992←16 Years→25 Mar 2008 | Dissolved | |
| Powermaster Products Limited Director • Engineer | 26 Mar 1990←18 Years→25 Mar 2008 | Dissolved | |
| Powermaster Cooling Limited Director • Engineer | 26 Jul 1989←18 Years→25 Mar 2008 | Active | |
