The valueInSpecifiedUnits property of the SVGLength interface represents floating point value, in the units expressed by unitType.
Setting this attribute will cause value and valueAsString to be updated automatically to reflect this setting.
The numeric factor of the length as a float.
// Get an SVGLength object
const svg = document.querySelector("svg");
const length = svg.createSVGLength();
// Set the value of the length
length.value = 10;
console.log(length.valueInSpecifiedUnits); // Output: 10
// Update the numeric factor of the length
length.valueInSpecifiedUnits = 20;
console.log(length.valueInSpecifiedUnits); // Output: 20