| 021 | K7766 | BRITISH STANDARDS INSTITUTION |
| 10177406 | A486G | NIMIKKEISTOKESKUS NCB FINLAND |
| ASCC17-27C-021 | 22937 | MOR-FLO INDUSTRIES INC |
| AMBEU61521 | D1131 | AUTOFLUG GMBH DBA AUTOFLUG SICHERHEITSGERATE |
| BS ISO 3601-1 SIZE 021 | K7766 | BRITISH STANDARDS INSTITUTION |
| AMBEU61521 | U1604 | MARTIN-BAKER AIRCRAFT COMPANY LIMITED |
| MBEU61521 | D1131 | AUTOFLUG GMBH DBA AUTOFLUG SICHERHEITSGERATE |
| BS ISO 3601-1 SIZE 021NBR.90 | K7766 | BRITISH STANDARDS INSTITUTION |
| BS1806-021 | K7766 | BRITISH STANDARDS INSTITUTION |
| BS1806-021NBR.90 | K7766 | BRITISH STANDARDS INSTITUTION |
| BSM48-021 | K7766 | BRITISH STANDARDS INSTITUTION |
| MBEU61521 | U1604 | MARTIN-BAKER AIRCRAFT COMPANY LIMITED |