Koenig,
.flex-direction-nav .flex-prev {
left: -5px;
-webkit-border-radius: 0 3px 3px 0;
-moz-border-radius: 0 3px 3px 0;
border-radius: 0 3px 3px 0;
z-index: 2;
}
.flex-direction-nav .flex-next {
right: -5px;
-webkit-border-radius: 3px 0 0 3px;
-moz-border-radius: 3px 0 0 3px;
border-radius: 3px 0 0 3px;
z-index: 2;
}