This is a Spektrum Aluminum 3.0" Double 23T Heavy-Duty Servo Arm. Spektrum Heavy Duty Aluminum Servo Arms are the perfect companion to your Spektrum outfitted model. Crafted with aircraft grade 7075-T6 CNC machined aluminum, these servo arms are strong enough to take the most brutal of abuse. And to ensure a tight link to your servo, the 23T spline mount is reinforced with a clamping design to prevent slipping. Along with a functional yet stylish finish and design, the Spektrum Heavy Duty Aluminum Servo Arms are sure to make your model stand out in the crowd.