Thank you. There are umpteen million connectors out there, and it's very challenging to identify them. Kudos to Dexter for including a very high quality 9V batter snap. Don't think I didn't notice!
Incidentally, on the circuit board, where it says "6V only", it would have been better if it had said "6V MAX" or even better "SERVO PWR". The text as is implies that you must supply 6 and only 6V, which of course isn't true, as it depends on the servo.