.carousel-control-prev-icon,
.carousel-control-next-icon {
    height: 60px;
    width: 60px;
    outline: black;
    background-size: 100%, 100%;
    border-radius: 50%;
    border: 1px solid black;
    background-image: none;
}

.carousel-control-next-icon:after
{
    content: '>';
    font-size: 35px;
    color: grey;
}

.carousel-control-prev-icon:after {
    content: '<';
    font-size: 35px;
    color: grey;
}