sentry/static/app/views/dashboardsV2/manage/gridPreview/chartPreviews/number.tsx

const NumberPreview = () => (
  <svg
    viewBox="0 0 70 17"
    xmlns="http://www.w3.org/2000/svg"
    fill="#444674"
    preserveAspectRatio="none"
    height="100%"
    width="100%"
  >
    <rect width="50" height="16" rx="1" />
  </svg>
);

export default NumberPreview;