Sign Decal Corrugated Metal 2x2
It's a sign. You write things on it.
Harvest drops
Iron× 10
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
When it collapses
Falling, it leaves 
Scrap Metal Pile (60% of the time) where it lands.
Where to find (17 POIs)
Navezgane County Jail (tier 5), Jeffelon Zuckergates Estate (tier 4), NFD Downtown HQ (tier 4), 4 Ever Video (tier 3), COC Chemicals (tier 3), Hogzilla Ranch LLC (tier 3), Law & Order Square (tier 3), Weston Weigh Station (tier 3), Collision Center (tier 2), Glove Affair Boxing Gym (tier 2), The Hoarders' House (tier 2), Dick's Diner (tier 1), Construction Warehouse, Mayor's Office, Patriot Pavilion, Shady Pointe Park, Westwood Place.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.