I looked on MFJ's site and could not find a listing for your keyer. The only one that came close I think is the econo keyer two. Look on page two of the manual, and it talks about the keying. Look in your radio manual and see what it requires. Copy and paste the following link and see if that what you are looking for
http://www.mfjenterprises.com/man/pdf/MFJ-401D.pdf