files/en-us/web/api/svgfespecularlightingelement/x/index.md
{{APIRef("SVG")}}
The x read-only property of the {{domxref("SVGFESpecularLightingElement")}} interface describes the horizontal coordinate of the position of an SVG filter primitive as a {{domxref("SVGAnimatedLength")}}.
It reflects the {{SVGAttr("x")}} attribute of the {{SVGElement("feSpecularLighting")}} element, which lights a source graphic using the alpha channel as a bump map. The attribute is a <length> or <percentage>. The <coordinate> is a length in the user coordinate system that is the given distance from the origin of the user coordinate system along the x-axis. If the x attribute is a percent value, the property value is relative to the width of the filter region in user coordinate system units. The default value is 0.
An {{domxref("SVGAnimatedLength")}}.
const feSpecularLighting = document.querySelector("feSpecularLighting");
const leftPosition = feSpecularLighting.x;
console.log(leftPosition.baseVal.value); // the `x` value
{{Specifications}}
{{Compat}}