Strengthened Glass Window

Glass goes in once you are tired of people looking into your base. An open window, or one with bars, shows a roamer where your boxes stand and lets him put bullets through the gap while you sort loot. This pane closes the gap and still lets you watch the yard.

It unlocks at a Level 2 workbench for 50 metal fragments a window, twice what metal window bars cost but without the hole. Research is 30 scrap. Late in the wipe the reinforced glass window takes over at a Level 3 bench, paid in high quality metal.

A typical moment: your 2x2 has grown into a two-storey base, and every time you come home someone is camping the window beside your door and shooting in. Swap that one for glass and the camping stops paying off. If you want your clan tag on it, the paintable window costs the same.