Pro Shorty Micro Servo Horn This is a great servo horn to be used on the 99Micro or 179 Micro Servo in the following vehicles: ARRMA Typhon Grom AARMA Granite Grom Mojave Grom Losi 1/12th NASCAR Features: REEFS Shield Design For 99Micro and 179Micro 25T Micro Spline CNC Machined Aluminum Anodized Finish Specifications: 21mm Long 13mm Servo Horn Screw to outside hole 2 Position Holes 2mm Threaded Holes