Printed in Clear, Grey, & Grey Pro resin on a Form 3. They're quite brittle.
You'll need one of these: 97258A103_18-8 Stainless Steel Thin Square Nut from McMaster
Get a radius gauge & input that measurement from your frame or fork into CAD.
You should not use this item to carry large loads (like racks).
The author marked this model as their own original creation.