The Window holder is a removable, easy to use window latch designed to keep a window slightly open for ventilation, preventing the window slamming in presence of wind.

Important: this window holder is solely designed for those windows that have installed en European STAC lock window system.
Here you can find a link to the STAC producer web page in addition to window lock pictures.

It doesn't require any tool, glue etc and can be removed any time. You can print this model in PLA or PETG as you prefer.