Great servo !
I've got mine for around a half year - it's simply the best servo I've ever got !
The servo comes with a normal servo wire, plus an additional 7,2 volt FET wire. I dont know Keyence - if it got a FET wire, then simply connect the two FET wires. Alternatively, solder the servo FET wire to the supplied choke coil, and solder the other end of the choke coil directly to the "+" on the battery (ONLY 6 cell !!!).
The servo comes with a little manual, that shows the above.