Commercially available superacids include trifluoromethanesulfonic acid (CFSOH), also known as triflic acid, and fluorosulfonic acid (FSOH). Both acids are about a thousand times stronger (that is, have more negative "H" values) than sulfuric acid. The strongest superacids are prepared by the combination of two components, a strong Lewis acid and a strong Brønsted acid. The strongest known superacid is fluoroantimonic acid.