Insert fits perfectly and the transparent part is clear to the point of being nearly invisible. The insert is a bit heavy (which is to be expected given the size of my window) and inserting it does take a bit of time and patience, which would be annoying if I'd want to frequently remove it in order to e.g. open a window, but luckily that is not the case for where I installed the inset. The main downsides are that it took a long time to receive the panel after I ordered it (making me hesitant to order a second one, even though I do have a second window that could use one) and they are not particularly cheap.