Redirect for one room

Hi

Regarding this code, how would you change it so that it only redirects for one particular room as it would currently redirect for all rooms. The Website will have 2 rooms and one of them has to be redirected elsewhere when checking Availability or when clicking the Book Now button.

function hotelier_custom_add_to_cart_from_room_list_redirect( $url ) {
    $custom_url = 'http://example.com';

    return $custom_url;
} 
add_filter( 'hotelier_add_to_cart_from_room_list_redirect', 'hotelier_custom_add_to_cart_from_room_list_redirect' );