This remote is discontinued, has upgrade to TM-27 .
The surface of GTX27 maybe same or similar with the surface of the remote GTXU1, GTXU2 , but totally are different each another and not compatible each other.
GTXU1, GTXU2 uses 6 volts battery.
TM-27 or GTX27 is using 12 volts battery.
This one has been upgraded to TM-27.