What is bunker buster bomb that Israel needs from US to destroy Iran’s nuclear sites?

What is bunker buster bomb that Israel needs from US to destroy Iran’s nuclear sites?

In the conflict with Iran, Israel's top goal is to destroy Iran's nuclear facilities. But that is no easy task. The Jewish nation might need the GBU-57A/B Massive Ordnance Penetrator (MOP) bunker buster bomb to damage these underground sites. But what do we know about the Boeing and US Air Force-made bomb? How effective is it?