Features: Designed specifically for cordless opt tracking T-RB22 mouse, ensuring a perfectly replace and making it easy for users to replace and repair. Precise control: providing a smooth and precise rolling experience, making the mouse more smoothly and freely on various surfaces. With excellent wear resistance, it can withstand long-term use without easy wear, extend its service life, and maintain long-term stable performances. Simple Installation: Designed to be user-friendly, users can easily replace without the need for professional tools or complicated steps, saving time and costs. Made with friendly to environment component that meet safety standards, they will not pose any health risks to users during use, ensuring their safety. Specifications: Component: ABS Color：As Pictures Diameter about 4.3cm/1.69in For: T RB22 Mouse Package Includes: 1PC Trackball replacement accessory note: Please allow 1-2cm errors due to manual measurement. Pictures may not reflect actual color due to different monitors