[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [Input](./puppeteer.protocol.input.md) > [DispatchMouseEventRequest](./puppeteer.protocol.input.dispatchmouseeventrequest.md) > [deltaY](./puppeteer.protocol.input.dispatchmouseeventrequest.deltay.md) ## Protocol.Input.DispatchMouseEventRequest.deltaY property Y delta in CSS pixels for mouse wheel event (default: 0). Signature: ```typescript deltaY?: number; ```