They are not the most dangerous thing Russia is using against Ukraine in this war, but they are arguably one of the scariest. They are Iranian-made Russian-launched drones. 

They are small…only about 9 feet by 9 feet.

They are relatively slow…they only travel at about a hundred miles an hour.

And they make a lot of noise…like a lawn mower or a moped.

However, they can be sent from a thousand miles away or more.

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When they crash into something, the hundred pounds plus of explosives on board packs a punch. Hence their nickname, "kamikaze" drones, after the Japanese World War 2 suicidal pilots.

"These drones are very dangerous for us," Ukrainian military intelligence officer "Vasily" told us, "They cause a lot of damage."

Vasily, with a balaclava halfway up his face, his identity withheld for security reasons, showed us around a room full of Iranian drones at a Ukrainian military complex in Kyiv. A bigger reconnaissance drone that also carries explosives. Bombs, engines, guidance devices.

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The small one is what we were focused on. The Iranian model name is "Shahed 136." When you’re up close to it, and you can touch and check it out…it seems pretty innocuous, made of cheap fiberglass, and painted a dull gray. The sort of thing you would watch model plane enthusiasts fly in a park on a Sunday afternoon.

However, hundreds of them have rained down on Ukraine. Locals can see and hear them coming. They experience the destruction, including against the electrical grid here that is blacking-out so much of this country now.

"We can see that these drones are aiming for critical infrastructure targets," Vasily explains.

The Ukrainians are getting pretty good at shooting them down with air defense systems; even sometimes with automatic rifles. Vasily showed me bits and pieces of drones that had been knocked out of the sky or had exploded on impact. 

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Still, hundreds if not thousands more of these relatively inexpensive drones are being sent by Iran to Russia. The fear is, as Ukrainian President Zelenskyy recently mentioned, of "mass attacks." That is, a dozen being at aimed at a target. Even if 11 are shot down, one can wreck it all.

"The air defense system will not be able to cope with this," Vasily admits.

As the fight, on many fronts, in many threatening shapes and sizes, goes on.