<? if ($arResult["PROPERTIES"]["DIMENSIONS"]["VALUE"]) { ?>
<div class="catalog-detail__options">
<select name="size">
<option disabled><?=GetMessage("SELECT_SIZE")?></option>
<? foreach($arResult["PROPERTIES"]["DIMENSIONS"]["VALUE"] as $size) { ?>
<option value="<?=$size?>"><?=$size?></option>
<? } ?>
</select>
</div>
<? } ?>
Add2BasketByProductID(
$PRODUCT_ID,
1,
array(
array("CODE" => "DIMENSIONS", "NAME" => "Размер", "VALUE" => $_POST['size']),
)
);