SOURCE

<div class="pulse-w">
    <div class="pulse"></div>
    <div class="pulse pulse2"></div>
</div>

.pulse-w {
    width: 100px;
    height: 100px;
    background: #777;
    pointer-events: none;
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: 214748;
    margin: auto;
}
.pulse {
    width: 100px;
    height: 100px;
    border-radius: 55%;
    background-color: #fff;
    opacity: .4;
    margin: auto;
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    transform: scale(0);
    -webkit-animation: pulse 1.5s ease-out infinite;
    animation: pulse 1.5s ease-out infinite;
}
.pulse2 {
    -webkit-animation-delay: -.35s;
    animation-delay: -.35s;
}
@-webkit-keyframes pulse {
  to {
    -webkit-transform: scale(1);
    opacity: 0;
  }
}
@keyframes pulse {
  to {
    -webkit-transform: scale(1);
    opacity: 0;
  }
}