These can be used on Y and Z Spec Sport Riders and Trail Rider racks. These support tubes will accommodate a bicycle up to a 72” wheelbase Y and Z spec is for racks that were sold between 2017 – Current The support tube is square 1.25" x 1.25" Distance between holes: 2.5" 32" length Sold as a pair If you're not sure what spec you have, please send a photo of your rack to info@hollywoodracks.com