This bomb is six times bigger than the one the USAF has had for years.

The Air Force has upgraded the United States’ largest non-nuclear bomb, a 30,000-pound “bunker-buster” capable of attacking hard and buried targets, according to Bloomberg Politics.

Also known as the Massive Ordnance Penetrator, the GBU-57 has just completed its fourth upgrade, and its inventory is being retrofitted, Air Force officials told Bloomberg.

The bunker-buster, which is manufactured by Boeing, can only be carried by the B-2 stealth bomber, and it can be used to hit nuclear or missile factories up to 200 feet underground.

Three B-2 bombers were deployed to Guam this month, which the Air Force says was a planned rotation. When asked by Bloomberg, Capt. Emily Grabowski, an Air Force spokeswoman, declined to say if the GBU-57 was aboard.

This comes less than a month from the Winter Olympics in Pyeongchang, South Korea, and amid negotiations between North and South Korea, noted Stars and Stripes.

The GBU-57 is six times bigger than the 5,000-pound bombs that have been used by the Air Force for years, and it carries more than 5,300 pounds of explosives, according to Bloomberg.

It is 20.5 feet long, encased in hardened steel, and guided by Global Positioning System satellites, according to a description on the website of the Pentagon’s Defense Threat Reduction Agency.