What kind of guitar did black sabbath use?

Tony Iommi, guitarist of Black Sabbath, started playing on a Gibson SG he had bought when he was 18, but it sustained irreparable damage due to flooding. He bought a replacement that was later stolen, causing him to design and build his own guitar, the "Monkey". Later he used modified SG's, particularly a custom clear plastic pick guard SG in the mid-'70s, and then various Gibson Les Pauls, mainly the Custom and Standard models.