Vintage Morse Code Telegraph Key The Rare Naval Lionel Blinker Traing JK 38. It has a small plaque on it. That says Bureau of Naval Personnel Bulkhead Blimker Navpers 4000 procured through Office of Naval Research Special Devices Center. It comes with papers explaining what it is and how it works. Also a Navy instruction sheet. It was used as a training devise. It has Naval symbol stamped on the bottom. It is in working condition. It measures in total 6 inches length 3 inches width.