Changing net of window "Amido"

Now we are in the middle of June, so I started to repair and change the net of window after a long time.

This net window protect from the mosquito getting into the room.

We, Sakuraya, have a lot of these windows, so we do it by ourselves.
Yes, this is a reasonable way.

By the way when we change the nets we usually use one thing.
Do you know it ? ......

This is it.

We, Japanese, call it "Osae roller", maybe you can find it at any home center in Japan.

We use this tool to push the net into the window's gutter (?).

If you change the net please prepair this useful tool.