The ‘clear opening’ is the opening created between the steel door frames when the door leaf is fully open. This is not the external frame size that you choose when ordering your security door set.
Our frame profile is 55mm in width when looking at the face of the door, therefore, to work out your clear opening size, minus 110mm (55mm each side) from your chosen external frame size. E.g. 895mm external frame will give you a clear opening of 785mm when the door is open at a 180 degree angle. If the door can only open to a 90 degree angle, minus an additional 50mm from 785mm.
For the clear opening height, remove 55mm from the external frame height (2020mm-55mm=1965mm)