Hard Flap Sizes

Size Flap Opening (HxW)
Small  240mm x 190mm
Medium 305mm x 225mm
Large  400mm x 260mm


Undo the top screws and one side screw, then gently pull the frame apart slightly. This will allow you to unslot the old flap and remove it. You can then pop the new flap into place and reinstall the screws.

The whole process only takes a few minutes and no special tools are required beyond a screwdriver.