.about_us_image{
  -webkit-mask-image:radial-gradient(
    farthest-side at 50% 50%,
    rgba(0,0,0,1) 70%,
    rgba(0,0,0,0) 100%
  );
  mask-image:radial-gradient(
    farthest-side at 50% 50%,
    rgba(0,0,0,1) 70%,
    rgba(0,0,0,0) 100%
  );
  -webkit-mask-size:100% 100%;
  mask-size:100% 100%;
  -webkit-mask-repeat:no-repeat;
  mask-repeat:no-repeat;
  -webkit-mask-composite:source-in;
  mask-composite:intersect;
}