Anna Kolchina

.wrap-clients {
    position: relative;
}
.wrap-clients::before {
    content: " ";
    position: absolute;
    left: -arrow.width - margin;
    // Прочие стили
}
.wrap-clients::after {
    content: " ";
    position: absolute;
    right: -arrow.width - margin; 
    // Прочие стили
}