H120 Class Fire Protection Rectangular Window:
| NO. | NOMINAL SIZE WXH | B.H. OPENING SIZE W1XH1XR1 | SIZE OF OUTSIDE W2XH2 | MAIN GLASS THICK. t | SIZE OF GLASS W3XH3XR3 | |
| HEAVY | MEDIUM | |||||
| 1 | 355X500 | 407X552XR76 | 515X660 | 10 | 8 | 415X560XR80 |
| 2 | 400X560 | 452X612XR76 | 560X720 | 12 | 8 | 460X620XR80 |
| 3 | 450X630 | 502X682XR126 | 610X790 | 12 | 8 | 510X690XR130 |
| 4 | 500X710 | 552X762XR126 | 660X870 | 15 | 10 | 560X770XR130 |
| 5 | 560X800 | 612X852XR126 | 720X960 | 15 | 10 | 620X860XR130 |
| 6 | 900X630 | 952X852XR126 | 1060X790 | 19 | 12 | 960X690XR130 |
| 7 | 1000X710 | 1052X762XR126 | 1160X870 | 19 | 12 | 1060X770XR130 |
| 8 | 1200X800 | 1252X852XR126 | 1360X960 | 19 | 15 | 1260X860XR130 |