The SRT-RC TR-X6S servo horn is a 25-tooth spline servo arm designed for use with compatible SRT servos. It provides a secure connection between the servo output shaft and linkage, making it a practical replacement or spare for a wide range of RC vehicles and helicopters. The 25T spline count is the key spec to match against your existing servo before ordering. Features: 25T spline interface Metal construction Compatible with a wide range of RC cars and helicopters Factory replacement for SRT TR-X6S servos 7/7/26 cs