I may have tried to get rid of this before - I do not recall. If so, here is another shot... I have an extra MX-1394/ARC-21 Adapter, Keyer Group doohickie available. This little box allows the AN/ARC-21 aircraft radio to use the AN/ARA-26 emergency Morse code keyer unit. A must have in any AN/ARC-21 situation. Any interest? -- Will