woocommerce_admin_stock_report_products_per_page filter-hook . WC 1.0

Usage

add_filter( 'woocommerce_admin_stock_report_products_per_page', 'filter_function_name_3025' );
function filter_function_name_3025( $20 ){
	// filter...

	return $20;
}

$20

-

Where the hook is called

$per_page              = apply_filters( 'woocommerce_admin_stock_report_products_per_page', 20 );

Where in WP core the hook is used WooCommerce