.wpb-content-layouts .wpb-layout-element-button .cq_allinone_tab {
    background-image: url(../img/icon_tab.png)!important;
    background-size: 32px;
}
.vc_element-icon.cq_allinone_tab{
    background-image: url(../img/icon_tab.png)!important;
    background-size: 32px;
}
.wpb_cq_vc_extension_tab.wpb_content_element > .wpb_element_wrapper {
    background-image: url(../img/icon_tab.png)!important;
    background-size: 32px;
}