This is a King 3B Concert F-Trigger trombone in good condition that dates between 1975-1980. The lacquer is about 80% in tact. There was a repair done on the knuckle going into the rotor that was expertly repaired. Otherwise, it's in very good shape. 
 
Plays as well as any 3B with plenty of power and brightness that this model is known for, but also is capable of beautiful soft tone. It slots very well and is overall an excellent player.
 
Comes with case.
 
Asking $875 + Shipping