The whole ball of wax. American light anti tank weapons. American mortars. Old Ukranian stock. Stuff Ukraine was assembling. Stuff from other EU countries. Huge anti tank missiles. Huge anti aircraft or whatever else missiles. Even Russian stuff. An entire warehouse full of spent casings to be reloaded. THE WHOLE BALL OF WAX, - AND MOST IMPORTANTLY, The Ukranian forces abandoned this which means they had no ability to relocate it before being overtaken. That means they are losing. There are enough weapons in this stache to win a war against a major power, the discovery was THAT BIG.
It is not just the first warehouse full at the beginning, they go through multiple warehouses and prove NATO is supplying Ukraine with a dream stache.