●Number of Teeth : 25T; Thickness : 5mm/0.2inch; Length : 18.5mm/0.73 inch, Big hole diameter : 3mm/0.12inch, Small hole diameter : 2mm/0.09inch, ●25 T Servo Horn is compatible with TRX4M 1/18 RC Crawler Car. ●Come with 4pcs screws to make sure servo horm clamp onto the servo output tightly, for your car or airplane joints. ●Aluminium alloy with hard anodized finish is durable and resistant to corrosion in many environments. ●The servo arm has 25 teeth. When the steering gear rocker arm and steering gear are fixed, these small teeth can play a good anti-skid effect