woo products per page

by 
//woo Change number of products that are displayed per page (shop page)

add_filter( 'loop_shop_per_page', 'new_loop_shop_per_page', 20 );
function new_loop_shop_per_page( $cols ) {
  // $cols contains the current number of products per page based on the value stored on Options –> Reading
  // Return the number of products you wanna show per page.
  $cols = 12;
  return $cols;
}