[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [CSS](./puppeteer.protocol.css.md) > [RuleUsage](./puppeteer.protocol.css.ruleusage.md) > [styleSheetId](./puppeteer.protocol.css.ruleusage.stylesheetid.md) ## Protocol.CSS.RuleUsage.styleSheetId property The css style sheet identifier (absent for user agent stylesheet and user-specified stylesheet rules) this rule came from. Signature: ```typescript styleSheetId: StyleSheetId; ```