Windows
Bulletproof Glass Ramp
Bulletproof Glass can be repaired but requires completely new blocks of the same type as repair material.
Crafting
Craft at Forge with 
Crucible · makes 1
Crafted as 
Bulletproof Glass Block: pick this one of its variants when you place it.
- Glass (forge units)× 112
- Stone (forge units)× 10
- Lead (forge units)× 40
- Iron (forge units)× 20
- Clay (forge units)× 20
Harvest drops
Broken Glass× 21
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
Where to find (1 POIs)
Hexagon Hideaway (tier 3).
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.