Stackable Ring

 *****    *****   ******    *****   ******    *****    *****   
*     *  *     *  *     *  *     *  *     *  *     *  *     *  
*        *        *     *  *        *     *  *     *  *     *  
 *****   *        *     *  *        ******   *     *  *     *  
      *  *        *     *  *        *     *  *     *  *   * *  
*     *  *     *  *     *  *     *  *     *  *     *  *    *   
 *****    *****   ******    *****   ******    *****    **** *