The servo rudder you are looking for is here, all sizes and mounting types are available!
Reference 09C-10114
Brand: CORALLY
TEAM CORALLY - SERVO SAVER - S MALL - 25 SPLINE - FUTABA - SA - C-101
Reference 05FAST311B
Brand: FASTRAX
25T BLACK ALUMINIUM SERVO HORN (SAVOX/FUTABA) - FAST311B
Reference 08293409
Brand: HUDY
ALU CLAMP SERVO HORN - FUTABA, SAVÖX - 3-HOLE M3 - 25T - 293409
Reference 08293443
Brand: HUDY
ALU CLAMP THROTTLE SERVO HORN - FUTABA, SAVÖX - OFFSET 2-HOLE M3 -25T
Reference 08293446
Brand: HUDY
ALU CLAMP THROTTLE SERVO HORN - FUTABA, SAVÖX - 2-HOLE - 25T - 293446
Reference 08293498
Brand: HUDY
ALU SERVO HORN - HITEC - 2-HOLE M3 - 24T - 293498
Reference 08293507
Brand: HUDY
ALU THROTTLE SERVO HORN - KO PROPO, SANWA - 2-HOLE M3 - 23T - 293507
Reference 08293508
Brand: HUDY
ALU THROTTLE SERVO HORN - HITEC - 2-HOLE M3 - 24T - 293508
Reference 09C-10121
Brand: CORALLY
TEAM CORALLY - SERVO SAVER - L ARGE - UNIVERSAL - 23-24-25 SP - C-101
Reference 08293413
Brand: HUDY
ALU CLAMP SERVO HORN - 2-HOLE - 25T - 293413
Reference 02UR1814-25
Brand: ULTIMATE
ALUMINUM THROTTLE SERVO HORN 25T - UR1814-25
Reference 08293444
Brand: HUDY
ALU CLAMP THROTTLE SERVO HORN - KO PROPO, SANWA - 2-HOLE - 23T - 2934