Walk your dog while riding your bike without holding the leash! With this simple, yet strong hook, your dog's leash can always stay in front of your bike and ensure a successful and safe walk with your best friend! This hook requires absolutely NO extra parts. Everything's 100% printed! Just print with your normal settings, because there are no supports or bridges! The hook fits handlebars of 2.5 cm in diameter. This hook has been tested on all three of my bikes and fits all of them. The caps for the hook are a bit larger than the actual attachment sites because my printer isn't very precise and the filament shrinks a little. Everyone's printer and filament are different. If the caps don't fit, print it at 99% if it was too big or 101% if it was too small.