Hi,

To add the SKU filed into product view page, please go to the file app\design\frontend\default\sns_lunar\template\catalog\product\view.phtml, add the code bellow

<?php $sku = Mage::getModel('catalog/product')->load($_product->getId())->getSku(); ?>
                    <p class="sku-product"><?php echo $sku; ?></p>

right before the code

<?php echo $this->getReviewsSummaryHtml($_product, false, true)?>

Thanks,