.catalog-product-view .product-info-main .product-add-form .product-options-wrapper .swatch-opt .swatch-attribute.size .swatch-attribute-options .swatch-option,
#mpquickview-popup .product-info-main .product-add-form .product-options-wrapper .swatch-opt .swatch-attribute.size .swatch-attribute-options .swatch-option, .product-item .product-item-info .product-item-details div[class^='swatch-opt-'] .swatch-attribute.size .swatch-attribute-options .swatch-option {
    width: 45px!important;
}