Amazing and rare clock by Self Winding Clock Company. The clock was designed specifically for Western Union as pictured on the dial. And, utilized as the Naval Observance Time.The clock winds every hour by vibrating for approximately 5-seconds. Strong tick and winding. The clock winding unit works off two-AAA batteries, approximately 5-6 volts. The clock was designed for accuracy and small winds every 60-minutes ads to the accuracy. All original clock in very good WOR...KING order. If you want the best self winding clock, this is it. PLEASE ASK ANY QUESTIONS BEFORE BIDDING. Approximate Dimensions: 20" L x 20" W x 10" D. Please look closely at the photos which are part of the listing description. Good luck bidding. WE ONLY SHIP WITHIN THE UNITED STATES.