The Universal Cycling Number Holder is designed to fit *most bikes. The Universal holder attaches to the rear of a Seat Post or ISP (Integrated Seat Post) and is a perfect addition for professional cycling and triathlons. We've taken extreme care in design for both style and functionality. You'll find that the Universal Number holder is constructed so no hardware sticks out beyond the edges; meaning no extra wind drag on the component during a ride. The Universal Number Holder attaches via zip tie. All of our 3d printed cycling number holder and other parts are made in our Tennessee, USA facility.