How to switch the number of elements per page?

Question

Yii

Required - Output of goods by: 10 20 30
How can such functionality be implemented in yii?
Element output

<? foreach($products as $product) : ?>
                <? $this->renderPartial('_item', array(
                    'product' => $product,
                    'section' => $section,
                    'price' => $price,
                )); ?>
            <? endforeach;?>