Here is the screwdriver I have used for years in the R-390 family. http://www.tselectronic.com/viewpage.php?filename=klein/phillipsdrvr.html&refpage=/vend_prod_list/klein.html&tse_Session=1d94fb7bf74cee0450063 It is a Klein P-18 Good Luck to all Don Heywood WC4G Charleston, SC