An electrosurgical instrument includes jaws having an electrode configuration utilized to electrically modify tissue in contact with one or more electrodes. The instrument is removably connectable to an electrosurgical unit via an electrosurgical connector extending from the instrument and a receptacle on the electrosurgical unit. The electrosurgical instrument is rotatable without disrupting electrical connection to the electrodes of the jaws. One or more of the electrodes is retractable. The electrosurgical unit and instrument optimally seals and/or cuts tissue based on identifying the tissue and monitoring the modification of the tissue by the application of radio frequency energy.