velcro
thingiverse
The model I'm running is created from a customized version of thing number 777131 on thingiverse.com. The creator used the Customizer app to design this object, and you can also customize it by using this link: https://www.thingiverse.com/apps/customizer/run?thing_id=777131.
Download Model from thingiverse
With this file you will be able to print velcro with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on velcro.