The Tacx Sram XD-R Freehub Body is designed specifically for use with Tacx Neo and Flux trainers, featuring a 6mm internal dimension axle hole for a secure and reliable fit. This durable and lightweight freehub body ensures long-lasting performance, making it an essential component for serious cyclists looking to enhance their indoor training experience. With easy installation, you can quickly set up your trainer and get back to your workouts without hassle.