Robert Axle Project Trainer Thru-Axle. Features: Zwift users rejoice, the perfect solution for modern thru-axle bikes and modern bike trainers Axle trainer attachments are removable so the trainer axle can be used on or off the trainer. Excellent for warm-up applications No special tools required for installation and removal, a simple 5mm hex key Machined to the high standards in the industry Use the Robert Axle Finder (below) to find the right axle When multiple axle lengths are listed, the axle includes one or two spacers. The different lengths are with and without the spacers Designed, tested and made in Bend Oregon Specifications: Description: 12mm Trainer Thru-Axle Brand Fitment: Mavic Speed Release Axle Length: 165mm Thread Pitch: Double Lead-in 1.0mm