UnTube/backend/main/static/svg-loaders/rings.svg

<!-- By Sam Herbert (@sherb), for everyone. More @ http://goo.gl/7AJzbL -->
<svg width="45" height="45" viewBox="0 0 45 45" xmlns="http://www.w3.org/2000/svg" stroke="#fff">
    <g fill="none" fill-rule="evenodd" transform="translate(1 1)" stroke-width="2">
        <circle cx="22" cy="22" r="6" stroke-opacity="0">
            <animate attributeName="r"
                 begin="1.5s" dur="3s"
                 values="6;22"
                 calcMode="linear"
                 repeatCount="indefinite" />
            <animate attributeName="stroke-opacity"
                 begin="1.5s" dur="3s"
                 values="1;0" calcMode="linear"
                 repeatCount="indefinite" />
            <animate attributeName="stroke-width"
                 begin="1.5s" dur="3s"
                 values="2;0" calcMode="linear"
                 repeatCount="indefinite" />
        </circle>
        <circle cx="22" cy="22" r="6" stroke-opacity="0">
            <animate attributeName="r"
                 begin="3s" dur="3s"
                 values="6;22"
                 calcMode="linear"
                 repeatCount="indefinite" />
            <animate attributeName="stroke-opacity"
                 begin="3s" dur="3s"
                 values="1;0" calcMode="linear"
                 repeatCount="indefinite" />
            <animate attributeName="stroke-width"
                 begin="3s" dur="3s"
                 values="2;0" calcMode="linear"
                 repeatCount="indefinite" />
        </circle>
        <circle cx="22" cy="22" r="8">
            <animate attributeName="r"
                 begin="0s" dur="1.5s"
                 values="6;1;2;3;4;5;6"
                 calcMode="linear"
                 repeatCount="indefinite" />
        </circle>
    </g>
</svg>