Hi, up for auction is a  BENDIX KING KT-76A TRANSPONDER  . It´s in excellent working condition, looks good and was only removed from the aircraft for an avionics upgrade. 
I guarantee this item for 30 days after auction end. If your not happy with it for any reason you can return it within 30 days of auction end for a full refund ( as long as the "void if broken" seals are still intact).