Match Height

match.js

jQuery(function() {
    // apply your matchHeight on DOM ready

    // apply matchHeight to each item container's items
    jQuery('.product_item_inner').each(function() {
        jQuery(this).children('.product_item_excerpt').matchHeight({
            byRow: true
        });
    });
});

Updated targeting:
// test target jQuery('.product_item').each(function() { jQuery(this).children('.product_item_inner').matchHeight({ target: jQuery(this).find('.product_item_excerpt') }); });