| 111 | K7766 | BRITISH STANDARDS INSTITUTION |
| 4A41-Y0-111 | U3341 | THOMPSON VALVES LTD |
| B0444 | K0207 | HALE HAMILTON (VALVES) LIMITED |
| BS1806 | K7766 | BRITISH STANDARDS INSTITUTION |
| BS1806-111 | K7766 | BRITISH STANDARDS INSTITUTION |
| BSM48-111 | K7766 | BRITISH STANDARDS INSTITUTION |